Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

73 files changed, 10492 insertions, 0 deletions

diff --git a/tools/tryselect/__init__.py b/tools/tryselect/__init__.py
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index 0000000000..c580d191c1
--- /dev/null
+++ b/tools/tryselect/__init__.py
@@ -0,0 +1,3 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
diff --git a/tools/tryselect/cli.py b/tools/tryselect/cli.py
new file mode 100644
index 0000000000..74c82c4bed
--- /dev/null
+++ b/tools/tryselect/cli.py
@@ -0,0 +1,167 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+import os
+import subprocess
+import tempfile
+from argparse import ArgumentParser
+
+from .task_config import all_task_configs
+
+COMMON_ARGUMENT_GROUPS = {
+    "push": [
+        [
+            ["-m", "--message"],
+            {
+                "const": "editor",
+                "default": "{msg}",
+                "nargs": "?",
+                "help": "Use the specified commit message, or create it in your "
+                "$EDITOR if blank. Defaults to computed message.",
+            },
+        ],
+        [
+            ["--closed-tree"],
+            {
+                "action": "store_true",
+                "default": False,
+                "help": "Push despite a closed try tree",
+            },
+        ],
+    ],
+    "preset": [
+        [
+            ["--save"],
+            {
+                "default": None,
+                "help": "Save selection for future use with --preset.",
+            },
+        ],
+        [
+            ["--preset"],
+            {
+                "default": None,
+                "help": "Load a saved selection.",
+            },
+        ],
+        [
+            ["--list-presets"],
+            {
+                "action": "store_const",
+                "dest": "preset_action",
+                "const": "list",
+                "default": None,
+                "help": "List available preset selections.",
+            },
+        ],
+        [
+            ["--edit-presets"],
+            {
+                "action": "store_const",
+                "dest": "preset_action",
+                "const": "edit",
+                "default": None,
+                "help": "Edit the preset file.",
+            },
+        ],
+    ],
+    "task": [
+        [
+            ["--full"],
+            {
+                "action": "store_true",
+                "default": False,
+                "help": "Use the full set of tasks as input to fzf (instead of "
+                "target tasks).",
+            },
+        ],
+        [
+            ["-p", "--parameters"],
+            {
+                "default": None,
+                "help": "Use the given parameters.yml to generate tasks, "
+                "defaults to a default set of parameters",
+            },
+        ],
+    ],
+}
+
+NO_PUSH_ARGUMENT_GROUP = [
+    [
+        ["--stage-changes"],
+        {
+            "dest": "stage_changes",
+            "action": "store_true",
+            "help": "Locally stage changes created by this command but do not "
+            "push to try.",
+        },
+    ],
+    [
+        ["--no-push"],
+        {
+            "dest": "dry_run",
+            "action": "store_true",
+            "help": "Do not push to try as a result of running this command (if "
+            "specified this command will only print calculated try "
+            "syntax and selection info and not change files).",
+        },
+    ],
+]
+
+
+class BaseTryParser(ArgumentParser):
+    name = "try"
+    common_groups = ["push", "preset"]
+    arguments = []
+    task_configs = []
+
+    def __init__(self, *args, **kwargs):
+        ArgumentParser.__init__(self, *args, **kwargs)
+
+        group = self.add_argument_group("{} arguments".format(self.name))
+        for cli, kwargs in self.arguments:
+            group.add_argument(*cli, **kwargs)
+
+        for name in self.common_groups:
+            group = self.add_argument_group("{} arguments".format(name))
+            arguments = COMMON_ARGUMENT_GROUPS[name]
+
+            # Preset arguments are all mutually exclusive.
+            if name == "preset":
+                group = group.add_mutually_exclusive_group()
+
+            for cli, kwargs in arguments:
+                group.add_argument(*cli, **kwargs)
+
+            if name == "push":
+                group_no_push = group.add_mutually_exclusive_group()
+                arguments = NO_PUSH_ARGUMENT_GROUP
+                for cli, kwargs in arguments:
+                    group_no_push.add_argument(*cli, **kwargs)
+
+        group = self.add_argument_group("task configuration arguments")
+        self.task_configs = {c: all_task_configs[c]() for c in self.task_configs}
+        for cfg in self.task_configs.values():
+            cfg.add_arguments(group)
+
+    def validate(self, args):
+        if hasattr(args, "message"):
+            if args.message == "editor":
+                if "EDITOR" not in os.environ:
+                    self.error(
+                        "must set the $EDITOR environment variable to use blank --message"
+                    )
+
+                with tempfile.NamedTemporaryFile(mode="r") as fh:
+                    subprocess.call([os.environ["EDITOR"], fh.name])
+                    args.message = fh.read().strip()
+
+            if "{msg}" not in args.message:
+                args.message = "{}\n\n{}".format(args.message, "{msg}")
+
+    def parse_known_args(self, *args, **kwargs):
+        args, remainder = ArgumentParser.parse_known_args(self, *args, **kwargs)
+        self.validate(args)
+        return args, remainder
diff --git a/tools/tryselect/docs/configuration.rst b/tools/tryselect/docs/configuration.rst
new file mode 100644
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+Configuring Try
+===============
+
+
+Getting Level 1 Commit Access
+-----------------------------
+
+In order to push to try, `Level 1 Commit Access`_ is required. Please see `Becoming a Mozilla
+Committer`_ for more information on how to obtain this.
+
+
+Configuring Version Control
+---------------------------
+
+After you have level 1 access, you'll need to do a little bit of setup before you can push. Both
+``hg`` and ``git`` are supported, move on to the appropriate section below.
+
+
+Configuring Try with Mercurial / Git
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The recommended way to push to try is via the ``mach try`` command. This requires the
+``push-to-try`` extension which can be installed by running:
+
+.. code-block:: shell
+
+    $ mach vcs-setup
+
+.. _Level 1 Commit Access: https://www.mozilla.org/en-US/about/governance/policies/commit/access-policy/
+.. _Becoming a Mozilla Committer: https://www.mozilla.org/en-US/about/governance/policies/commit/
diff --git a/tools/tryselect/docs/img/add-new-jobs.png b/tools/tryselect/docs/img/add-new-jobs.png
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index 0000000000..513565cb14
--- /dev/null
+++ b/tools/tryselect/docs/img/add-new-jobs.png
diff --git a/tools/tryselect/docs/img/phab-treeherder-link.png b/tools/tryselect/docs/img/phab-treeherder-link.png
new file mode 100644
index 0000000000..52b58b6231
--- /dev/null
+++ b/tools/tryselect/docs/img/phab-treeherder-link.png
diff --git a/tools/tryselect/docs/index.rst b/tools/tryselect/docs/index.rst
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+Pushing to Try
+==============
+
+"Pushing to Try" allows developers to build and test their changes on Mozilla's automation servers
+without requiring their code to be reviewed and landed.
+
+First, :doc:`ensure that you can push to Try <configuration>`.
+Try knows how to run tasks that are defined in-tree,
+such as ``build-linux64/opt`` (build Firefox for Linux). To manually select some tasks for
+Try to process, run the following command:
+
+.. code-block:: shell
+
+    ./mach try fuzzy
+
+After submitting your requested tasks, you'll be given a link to your "push" in Treeherder.
+It may take a few minutes for your push to appear in Treeherder! Be patient, and it will automatically
+update when Try begins processing your work.
+
+Another very useful Try command is ``./mach try auto``, which will automatically select the tasks
+that are mostly likely to be affected by your changes.
+See the :doc:`selectors page <selectors/index>` to view all the other ways to select which tasks to push.
+
+Resolving "<Try build> is damaged and can't be opened" error
+------------------------------------------------------------
+
+Apple automatically quarantines apps that are downloaded with a browser from an untrusted
+location. This "quarantine status" can be cleared by doing ``xattr -c <Try build>`` after
+downloading. You can avoid this "quarantine status" by downloading the build from the command
+line instead, such as by using ``curl``:
+
+.. code-block:: shell
+
+    curl -L <artifact-url> -o <file-name>
+
+.. _attach-job-review:
+
+Adding Try jobs to a Phabricator patch
+--------------------------------------
+
+For every patch submitted for review in Phabricator, a new Try run is automatically created.
+A link called ``Treeherder Jobs`` can be found in the ``Diff Detail`` section of the review in
+Phabricator.
+
+.. image:: img/phab-treeherder-link.png
+
+This run is created for static analysis, linting and other tasks. Attaching new jobs to the run is
+easy and doesn't require more actions from the developer.
+Click on the down-arrow to access the actions menu, select the relevant jobs
+and, click on ``Trigger X new jobs`` (located on the top of the job).
+
+.. image:: img/add-new-jobs.png
+
+Table of Contents
+-----------------
+
+.. toctree::
+  :maxdepth: 2
+
+  configuration
+  selectors/index
+  presets
+  tasks
+
+
+Indices and tables
+------------------
+
+* :ref:`genindex`
+* :ref:`modindex`
+* :ref:`search`
diff --git a/tools/tryselect/docs/presets.rst b/tools/tryselect/docs/presets.rst
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+++ b/tools/tryselect/docs/presets.rst
@@ -0,0 +1,85 @@
+Presets
+=======
+
+Some selectors, such as ``fuzzy`` and ``syntax``, allow saving and loading presets from a file. This is a
+good way to re-use a selection, either at a later date or by sharing with others. Look for a
+'preset' section in ``mach <selector> --help`` to determine whether the selector supports this
+functionality.
+
+Using Presets
+-------------
+
+To save a preset, run:
+
+.. code-block:: shell
+
+    $ mach try <selector> --save <name> <args>
+
+For example, to save a preset that selects all Windows mochitests:
+
+.. code-block:: shell
+
+    $ mach try fuzzy --save all-windows-mochitests --query "'win 'mochitest"
+    preset saved, run with: --preset=all-windows-mochitests
+
+Then run that saved preset like this:
+
+.. code-block:: shell
+
+    $ mach try --preset all-windows-mochitests
+
+To see a list of all available presets run:
+
+.. code-block:: shell
+
+    $ mach try --list-presets
+
+
+Editing and Sharing Presets
+---------------------------
+
+Presets can be defined in one of two places, in your home directory or in a file checked into
+mozilla-central.
+
+Local Presets
+~~~~~~~~~~~~~
+
+These are defined in your ``$MOZBUILD_STATE_DIR``, typically ``~/.mozbuild/try_presets.yml``.
+Presets defined here are your own personal collection of presets. You can modify them by running:
+
+.. code-block:: shell
+
+    $ ./mach try --edit-presets
+
+
+Shared Presets
+~~~~~~~~~~~~~~
+
+You can also check presets into mozilla-central in `tools/tryselect/try_presets.yml`_. These presets
+will be available to all users of ``mach try``, so please be mindful when editing this file. Make
+sure the name of the preset is scoped appropriately (i.e doesn't contain any team or module specific
+terminology). It is good practice to prefix the preset name with the name of the team or module that
+will get the most use out of it.
+
+
+Preset Format
+~~~~~~~~~~~~~
+
+Presets are simple key/value objects, with the name as the key and a metadata object as the value.
+For example, the preset saved above would look something like this in ``try_presets.yml``:
+
+.. code-block:: yaml
+
+    all-windows-mochitests:
+        selector: fuzzy
+        description: >-
+            Runs all windows mochitests.
+        query:
+            - "'win 'mochitest"
+
+The ``selector`` key (required) allows ``mach try`` to determine which subcommand to dispatch to.
+The ``description`` key (optional in user presets but required for shared presets) is a human
+readable string describing what the preset selects and when to use it. All other values in the
+preset are forwarded to the specified selector as is.
+
+.. _tools/tryselect/try_presets.yml: https://searchfox.org/mozilla-central/source/tools/tryselect/try_presets.yml
diff --git a/tools/tryselect/docs/selectors/again.rst b/tools/tryselect/docs/selectors/again.rst
new file mode 100644
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+++ b/tools/tryselect/docs/selectors/again.rst
@@ -0,0 +1,36 @@
+Again Selector
+==============
+
+When you push to try, the computed ``try_task_config.json`` is saved in a
+history file under ``~/.mozbuild/srcdirs/<srcdir hash>/history`` (note: the
+``syntax`` selector does not use ``try_task_config.json`` yet so does not save
+any history). You can then use the ``again`` selector to re-push any of your
+previously generated task configs.
+
+In the simple case, you can re-run your last try push with:
+
+.. code-block:: shell
+
+    $ mach try again
+
+If you want to re-push a task config a little further down the history stack,
+first you need to figure out its index with:
+
+.. code-block:: shell
+
+    $ mach try again --list
+
+Then run:
+
+.. code-block:: shell
+
+    $ mach try again --index <index>
+
+Note that index ``0`` is always the most recent ``try_task_config.json`` in the
+history. You can clear your history with:
+
+.. code-block:: shell
+
+    $ mach try again --purge
+
+Only the 10 most recent pushes will be saved in your history.
diff --git a/tools/tryselect/docs/selectors/auto.rst b/tools/tryselect/docs/selectors/auto.rst
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+++ b/tools/tryselect/docs/selectors/auto.rst
@@ -0,0 +1,24 @@
+Auto Selector
+=============
+
+This selector automatically determines the most efficient set of tests and
+tasks to run against your push. It accomplishes this via a combination of
+machine learning and manual heuristics. The tasks selected here should match
+pretty closely to what would be scheduled if your patch were pushed to
+autoland.
+
+It is the officially recommended selector to use when you are unsure of which
+tasks should run on your push.
+
+To use:
+
+.. code-block::
+
+   $ mach try auto
+
+Unlike other try selectors, tasks are not chosen locally. Rather they will be
+computed by the decision task.
+
+Like most other selectors, ``mach try auto`` supports many of the standard
+templates such as ``--artifact`` or ``--env``. See ``mach try auto --help`` for
+the full list of supported templates.
diff --git a/tools/tryselect/docs/selectors/chooser.rst b/tools/tryselect/docs/selectors/chooser.rst
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+++ b/tools/tryselect/docs/selectors/chooser.rst
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+Chooser Selector
+================
+
+When pushing to try, there are a very large amount of builds and tests to choose from. Often too
+many to remember, making it easy to forget a set of tasks which should otherwise have been run.
+
+This selector allows you to select tasks from a web interface that lists all the possible build and
+test tasks and allows you to select them from a list. It is similar in concept to the old `try
+syntax chooser`_ page, except that the values are dynamically generated using the :ref:`taskgraph<TaskCluster Task-Graph Generation>` as an
+input. This ensures that it will never be out of date.
+
+To use:
+
+.. code-block:: shell
+
+    $ mach try chooser
+
+This will spin up a local web server (using Flask) which serves the chooser app. After making your
+selection, simply press ``Push`` and the rest will be handled from there. No need to copy/paste any
+syntax strings or the like.
+
+You can run:
+
+.. code-block:: shell
+
+    $ mach try chooser --full
+
+To generate the interface using the full :ref:`taskgraph<TaskCluster Task-Graph Generation>` instead. This will include tasks that don't run
+on mozilla-central.
+
+
+.. _try syntax chooser: https://mozilla-releng.net/trychooser
diff --git a/tools/tryselect/docs/selectors/compare.rst b/tools/tryselect/docs/selectors/compare.rst
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+++ b/tools/tryselect/docs/selectors/compare.rst
@@ -0,0 +1,17 @@
+Compare Selector
+================
+
+When this command runs it pushes two identical try jobs to treeherder. The first
+job is on the current commit you are on, and the second one is a commit
+specified in the command line arguments. This selector is aimed at helping
+engineers test performance enhancements or resolve performance regressions.
+
+Currently the only way you can select jobs is through fuzzy but we are
+planning on expanding to other choosing frameworks also.
+
+You pass the commit you want to compare against as a commit hash as either
+``-cc`` or ``--compare-commit``, an example is show below
+
+.. code-block:: shell
+
+   $ mach try compare --compare-commit <commit-hash>
diff --git a/tools/tryselect/docs/selectors/empty.rst b/tools/tryselect/docs/selectors/empty.rst
new file mode 100644
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+++ b/tools/tryselect/docs/selectors/empty.rst
@@ -0,0 +1,21 @@
+Empty Selector
+==============
+
+The ``mach try empty`` subcommand is very simple, it won't schedule any additional tasks. You'll
+still see lint tasks and python-unittest tasks if applicable, this is due to a configuration option
+in taskcluster.
+
+Other than those, your try run will be empty. You can use treeherder's ``Add new jobs`` feature to
+selectively add additional tasks after the fact.
+
+.. note::
+
+    To use ``Add new jobs`` you'll need to be logged in and have commit access level 1, just as if
+    you were pushing to try.
+
+To do this:
+
+    1. Click the drop-down arrow at the top right of your commit.
+    2. Select ``Add new jobs`` (it may take a couple seconds to load).
+    3. Choose your desired tasks by clicking them one at a time.
+    4. At the top of your commit, select ``Trigger New Jobs``.
diff --git a/tools/tryselect/docs/selectors/fuzzy.rst b/tools/tryselect/docs/selectors/fuzzy.rst
new file mode 100644
index 0000000000..d50f801eb0
--- /dev/null
+++ b/tools/tryselect/docs/selectors/fuzzy.rst
@@ -0,0 +1,371 @@
+Fuzzy Selector
+==============
+
+The fuzzy selector uses a tool called `fzf`_. It allows you to filter down all of the task labels
+from a terminal based UI and an intelligent fuzzy finding algorithm. If the ``fzf`` binary is not
+installed, you'll be prompted to bootstrap it on first run.
+
+
+Understanding the Interface
+---------------------------
+
+When you run ``mach try fuzzy`` an interface similar to the one below will open. This is `fzf`_.
+
+.. image:: fzf.png
+
+There's a lot to unpack here, so let's examine each component a bit more closely.
+
+   A. The set of tasks that match the currently typed-out query. In the above image only tasks that
+   match the query ``'linux64 mochibrochr`` are displayed.
+
+   B. The set of selected tasks. These are the tasks that will be scheduled once you hit ``Enter``.
+   In other words, if the task you want does not appear here, *it won't be scheduled*.
+
+   C. Count information of the form ``x/y (z)``, where ``x`` is the number of tasks that match the
+   current query, ``y`` is the total number of tasks and ``z`` is the number of tasks you have
+   selected.
+
+   D. The input bar for entering queries. As you type you'll notice the list of tasks in ``A``
+   starts to update immediately. In the image above, the query ``'linux64 mochibrochr`` is entered.
+   Correspondingly only tasks matching that query are displayed.
+
+In general terms, you first find tasks on the left. Then you move them over to the right by
+selecting them. Once you are satisfied with your selection, press ``Enter`` to push to try.
+
+
+Selecting Tasks
+---------------
+
+There are few ways you can select tasks. If you are feeling a bit overwhelmed, it might be best to
+stick with the mouse to start:
+
+   1. Enter a query (e.g ``mochitest``) to reduce the task list a little.
+   2. Scroll up and look for the task(s) you want.
+   3. ``Right-Click`` as many tasks as desired to select them.
+   4. Optionally delete your query, go back to step 1) and repeat.
+   5. Press ``Enter`` to push (or ``Esc`` to cancel).
+
+.. note::
+
+   Dependencies are automatically filled in, so you can select a test task without needing
+   to select the build it depends on.
+
+As you ``Right-Click``, notice that a little arrow appears to the left of the task label. This
+indicates that the task is selected and exists in the preview pane to the right.
+
+Once you are a bit more comfortable with the interface, using the keyboard is much better at quickly
+selecting tasks. Here are the main shortcuts you'll need:
+
+.. code-block:: text
+
+    Ctrl-K / Up    => Move cursor up
+    Ctrl-J / Down  => Move cursor down
+    Tab            => Select task + move cursor down
+    Shift-Tab      => Select task + move cursor up
+    Ctrl-A         => Select all currently filtered tasks
+    Ctrl-T         => Toggle select all currently filtered tasks
+    Ctrl-D         => De-select all selected tasks (both filtered and not)
+    Alt-Bspace     => Clear query from input bar
+    Enter          => Accept selection and exit
+    Ctrl-C / Esc   => Cancel selection and exit
+    ?              => Toggle preview pane
+
+
+The process for selecting tasks is otherwise the same as for a mouse. A particularly fast and
+powerful way to select tasks is to:
+
+.. code-block:: text
+
+    Write a precise query => Ctrl-A => Alt-Bspace => Repeat
+
+As before, when you are satisfied with your selection press ``Enter`` and all the tasks in the
+preview pane will be pushed to try. If you change your mind you can press ``Esc`` or ``Ctrl-C`` to
+exit the interface without pushing anything.
+
+.. note::
+
+   Initially ``fzf`` will automatically select whichever task is under your cursor. This is a
+   convenience feature for the case where you are only selecting a single task. This feature will be
+   turned off as soon as you *lock in* a selection with ``Right-Click``, ``Tab`` or ``Ctrl-A``.
+
+
+Writing Queries
+---------------
+
+Queries are built from a series of terms, each separated by a space. Terms are logically joined by
+the AND operator. For example:
+
+.. code-block:: text
+
+    'windows 'mochitest
+
+This query has two terms, and is the equivalent of saying: Give me all the tasks that match both the
+term ``'windows'`` and the term ``'mochitest'``. In other words, this query matches all Windows
+mochitest tasks.
+
+The single quote prefix before each term tells ``fzf`` to use exact substring matches, so only tasks
+that contain both the literal string ``windows`` AND the literal string ``mochitest`` will be
+matched.
+
+Another thing to note is that the order of the terms makes no difference, so ``'windows 'mochitest``
+and ``'mochitest 'windows`` are equivalent.
+
+
+Fuzzy terms
+~~~~~~~~~~~
+
+If a term is *not* prefixed with a single quote, that makes it a fuzzy term. This means the
+characters in the term need to show up in order, but not in sequence. E.g the fuzzy term ``max``
+would match the string ``mozilla firefox`` (as first there is an ``m``, then an ``a`` and finally an
+``x``), but not the string ``firefox by mozilla`` (since the ``x`` is now out of order). Here's a
+less contrived example:
+
+.. code-block:: text
+
+    wndws mchtst
+
+Like the query above, this one would also select all Windows mochitest tasks. But it will
+additionally select:
+
+.. code-block:: text
+
+    test-macosx1014-64-shippable/opt-talos-sessionrestore-many-windows-e10s
+
+This is because both sequences of letters (``wndws`` and ``mchtst``) independently appear in order
+somewhere in this string (remember the order of the terms makes no difference).
+
+At first fuzzy terms may not seem very useful, but they are actually extremely powerful! Let's use
+the term from the interface image above, ``'linux64 mochibrochr``, as an example. First, just notice
+how in the image ``fzf`` highlights the characters that constitute the match in green. Next, notice
+how typing ``mochibrochr`` can quickly get us all mochitest browser-chrome tasks. The power of fuzzy
+terms is that you don't need to memorize the exact task labels you are looking for. Just start
+typing something you think is vaguely correct and chances are you'll see the task you're looking for.
+
+
+Term Modifiers
+~~~~~~~~~~~~~~
+
+The following modifiers can be applied to a search term:
+
+.. code-block:: text
+
+    'word    => exact match (line must contain the literal string "word")
+    ^word    => exact prefix match (line must start with literal "word")
+    word$    => exact suffix match (line must end with literal "word")
+    !word    => exact negation match (line must not contain literal "word")
+    'a | 'b  => OR operator (joins two exact match operators together)
+
+For example:
+
+.. code-block:: text
+
+    ^start 'exact | 'other !ignore fuzzy end$
+
+would match the string:
+
+.. code-block:: text
+
+    starting to bake isn't exactly fun, but pizza is yummy in the end
+
+.. note::
+
+    The best way to learn how to write queries is to run ``mach try fuzzy --no-push`` and play
+    around with all of these modifiers!
+
+
+Specifying Queries on the Command Line
+--------------------------------------
+
+Sometimes it's more convenient to skip the interactive interface and specify a query on the command
+line with ``-q/--query``. This is equivalent to opening the interface then typing:
+``<query><ctrl-a><enter>``.
+
+For example:
+
+.. code-block:: shell
+
+    # selects all mochitest tasks
+    $ mach try fuzzy --query "mochitest"
+
+You can pass in multiple queries at once and the results of each will be joined together:
+
+.. code-block:: shell
+
+    # selects all mochitest and reftest tasks
+    $ mach try fuzzy -q "mochitest" -q "reftest"
+
+If instead you want the intersection of queries, you can pass in ``-x/--and``:
+
+.. code-block:: shell
+
+    # selects all windows mochitest tasks
+    $ mach try fuzzy --and -q "mochitest" -q "windows"
+
+
+Modifying Presets
+~~~~~~~~~~~~~~~~~
+
+:doc:`Presets <../presets>` make it easy to run a pre-determined set of tasks. But sometimes you
+might not want to run that set exactly as is, you may only want to use the preset as a starting
+point then add or remove tasks as needed. This can be accomplished with ``-q/--query`` or
+``-i/--interactive``.
+
+Here are some examples of adding tasks to a preset:
+
+.. code-block:: shell
+
+    # selects all perf tasks plus all mochitest-chrome tasks
+    $ mach try fuzzy --preset perf -q "mochitest-chrome"
+
+    # adds tasks to the perf preset interactively
+    $ mach try fuzzy --preset perf -i
+
+Similarly, ``-x/--and`` can be used to filter down a preset by taking the intersection of the two
+sets:
+
+.. code-block:: shell
+
+    # limits perf tasks to windows only
+    $ mach try fuzzy --preset perf -xq "windows"
+
+    # limits perf tasks interactively
+    $ mach try fuzzy --preset perf -xi
+
+
+Shell Conflicts
+~~~~~~~~~~~~~~~
+
+Unfortunately ``fzf``'s query language uses some characters (namely ``'``, ``!`` and ``$``) that can
+interfere with your shell when using ``-q/--query``. Below are some tips for how to type out a query
+on the command line.
+
+The ``!`` character is typically used for history expansion. If you don't use this feature, the
+easiest way to specify queries on the command line is to disable it:
+
+.. code-block:: shell
+
+    # bash
+    $ set +H
+    $ ./mach try fuzzy -q "'foo !bar"
+
+    # zsh
+    $ setopt no_banghist
+    $ ./mach try fuzzy -q "'foo !bar"
+
+If using ``bash``, add ``set +H`` to your ``~/.bashrc``, ``~/.bash_profile`` or equivalent. If using
+``zsh``, add ``setopt no_banghist`` to your ``~/.zshrc`` or equivalent.
+
+If you don't want to disable history expansion, you can escape your queries like this:
+
+.. code-block:: shell
+
+    # bash
+    $ ./mach try fuzzy -q $'\'foo !bar'
+
+    # zsh
+    $ ./mach try fuzzy -q "'foo \!bar"
+
+
+The third option is to use ``-e/--exact`` which reverses the behaviour of the ``'`` character (see
+:ref:`additional-arguments` for more details). Using this flag means you won't need to escape the
+``'`` character as often and allows you to run your queries like this:
+
+.. code-block:: shell
+
+    # bash and zsh
+    $ ./mach try fuzzy -eq 'foo !bar'
+
+This method is only useful if you find you almost always prefix terms with ``'`` (and rarely use
+fuzzy terms). Otherwise as soon as you want to use a fuzzy match you'll run into the same problem as
+before.
+
+.. note:: All the examples in these three approaches will select the same set of tasks.
+
+If you use ``fish`` shell, you won't need to escape ``!``, however you will need to escape ``$``:
+
+.. code-block:: shell
+
+    # fish
+    $ ./mach try fuzzy -q "'foo !bar baz\$"
+
+
+Test Paths
+----------
+
+One or more paths to a file or directory may be specified as positional arguments. When
+specifying paths, the list of available tasks to choose from is filtered down such that
+only suites that have tests in a specified path can be selected. Notably, only the first
+chunk of each suite/platform appears. When the tasks are scheduled, only tests that live
+under one of the specified paths will be run.
+
+.. note::
+
+    When using paths, be aware that all tests under the specified paths will run in the
+    same chunk. This might produce a different ordering from what gets run on production
+    branches, and may yield different results.
+
+    For suites that restart the browser between each manifest (like mochitest), this
+    shouldn't be as big of a concern.
+
+Paths can be used with the interactive ``fzf`` window, or using the ``-q/--query`` argument.
+For example, running:
+
+.. code-block:: shell
+
+    $ mach try fuzzy layout/reftests/reftest-sanity -q "!pgo !cov !asan 'linux64"
+
+Would produce the following ``try_task_config.json``:
+
+.. code-block:: json
+
+    {
+      "env":{
+        "MOZHARNESS_TEST_PATHS":"{\"reftest\":\"layout/reftests/reftest-sanity\"}"
+      },
+      "tasks":[
+        "test-linux64-qr/debug-reftest-e10s-1",
+        "test-linux64-qr/opt-reftest-e10s-1",
+        "test-linux64/debug-reftest-e10s-1",
+        "test-linux64/debug-reftest-no-accel-e10s-1",
+        "test-linux64/opt-reftest-e10s-1",
+        "test-linux64/opt-reftest-no-accel-e10s-1",
+      ]
+    }
+
+Inside of these tasks, the reftest harness will only run tests that live under
+``layout/reftests/reftest-sanity``.
+
+
+.. _additional-arguments:
+
+Additional Arguments
+--------------------
+
+There are a few additional command line arguments you may wish to use:
+
+``-e/--exact``
+By default, ``fzf`` treats terms as a fuzzy match and prefixing a term with ``'`` turns it into an exact
+match. If passing in ``--exact``, this behaviour is reversed. Non-prefixed terms become exact, and a
+``'`` prefix makes a term fuzzy.
+
+``--full``
+By default, only target tasks (e.g tasks that would normally run on mozilla-central)
+are generated. Passing in ``--full`` allows you to select from all tasks. This is useful for
+things like nightly or release tasks.
+
+``-u/--update``
+Update the bootstrapped ``fzf`` binary to the latest version.
+
+For a full list of command line arguments, run:
+
+.. code-block:: shell
+
+    $ mach try fuzzy --help
+
+For more information on using ``fzf``, run:
+
+.. code-block:: shell
+
+    $ man fzf
+
+.. _fzf: https://github.com/junegunn/fzf
diff --git a/tools/tryselect/docs/selectors/fzf.png b/tools/tryselect/docs/selectors/fzf.png
new file mode 100644
index 0000000000..a64f4b04f3
--- /dev/null
+++ b/tools/tryselect/docs/selectors/fzf.png
diff --git a/tools/tryselect/docs/selectors/index.rst b/tools/tryselect/docs/selectors/index.rst
new file mode 100644
index 0000000000..be618202d6
--- /dev/null
+++ b/tools/tryselect/docs/selectors/index.rst
@@ -0,0 +1,44 @@
+Selectors
+=========
+
+These are the currently implemented try selectors:
+
+* :doc:`auto <auto>`: Have tasks chosen for you automatically.
+* :doc:`fuzzy <fuzzy>`: Select tasks using a fuzzy finding algorithm and
+  a terminal interface.
+* :doc:`chooser <chooser>`: Select tasks using a web interface.
+* :doc:`again <again>`: Re-run a previous ``try_task_config.json`` based
+  push.
+* :doc:`empty <empty>`: Don't select any tasks. Taskcluster will still run
+  some tasks automatically (like lint and python unittest tasks). Further tasks
+  can be chosen with treeherder's ``Add New Jobs`` feature.
+* :doc:`syntax <syntax>`: Select tasks using classic try syntax.
+* :doc:`release <release>`: Prepare a tree for doing a staging release.
+* :doc:`scriptworker <scriptworker>`: Run scriptworker tasks against a recent release.
+* :doc:`compare <compare>`: Push two identical try jobs, one on your current commit and another of your choice
+
+You can run them with:
+
+.. code-block:: shell
+
+    $ mach try <selector>
+
+See selector specific options by running:
+
+.. code-block:: shell
+
+    $ mach try <selector> --help
+
+.. toctree::
+  :caption: Available Selectors
+  :maxdepth: 1
+  :hidden:
+
+  Auto <auto>
+  Fuzzy <fuzzy>
+  Chooser <chooser>
+  Again <again>
+  Empty <empty>
+  Syntax <syntax>
+  Release <release>
+  Scriptworker <scriptworker>
diff --git a/tools/tryselect/docs/selectors/release.rst b/tools/tryselect/docs/selectors/release.rst
new file mode 100644
index 0000000000..946266249b
--- /dev/null
+++ b/tools/tryselect/docs/selectors/release.rst
@@ -0,0 +1,31 @@
+Release Selector
+================
+
+This command configures the tree in preparation for doing a staging release,
+and pushes the result to try. The changes that that are made include:
+
+- Updating the version number.
+- Applying the migrations that are done as part of merge day.
+- Disabling repacking most locales. (This can be disabled by passing ``--no-limit-locales``).
+
+For staging a beta release, run the following (with an appropriate version number):
+
+.. code-block:: shell
+
+   $ mach try release --version 64.0b5 --migration central-to-beta
+
+For staging a final release (rc or patch), run the following (with an appropriate version number)
+
+.. code-block:: shell
+
+   $ mach try release --version 64.0 --migration central-to-beta --migration beta-to-release
+
+Once the decision task is on the push is complete, you can start the release
+through `staging ship-it instance <https://shipit.staging.mozilla-releng.net/new>`_\ [#shipit]_.
+
+.. note::
+
+   If pushing from beta or release, the corresponding migration should not be
+   passed, as they have already been applied.
+
+.. [#shipit] This is only available to release engineering and release management (as of 2018-10-15).
diff --git a/tools/tryselect/docs/selectors/scriptworker.rst b/tools/tryselect/docs/selectors/scriptworker.rst
new file mode 100644
index 0000000000..a3cba08cbe
--- /dev/null
+++ b/tools/tryselect/docs/selectors/scriptworker.rst
@@ -0,0 +1,31 @@
+Scriptworker Selector
+=====================
+
+This command runs a selection of scriptworker tasks against builds from a
+recent release.  This is aimed at release engineering, to test changes to
+scriptworker implementations. It currently requires being connected to
+Mozilla's internal datacenter VPN with access to shipit\ [#shipit]_.
+
+There are a number of preset groups of tasks to run. To run a particular
+set of tasks, pass the name of the set to ``mach try scriptworker``:
+
+.. code-block:: shell
+
+   $ mach try scriptworker linux-signing
+
+To get the list of task sets, along with the list of tasks they will run:
+
+.. code-block:: shell
+
+   $ mach try scriptworker list
+
+The selector defaults to using tasks from the most recent beta, to use tasks
+from a different release, pass ``--release-type <release-type>``:
+
+.. code-block:: shell
+
+   $ mach try scriptworker --release-type release linux-signing
+
+
+.. [#shipit] The shipit API is not currently publicly available, and is used
+   to find the release graph to pull previous tasks from.
diff --git a/tools/tryselect/docs/selectors/syntax.rst b/tools/tryselect/docs/selectors/syntax.rst
new file mode 100644
index 0000000000..b64bb65ab7
--- /dev/null
+++ b/tools/tryselect/docs/selectors/syntax.rst
@@ -0,0 +1,41 @@
+Syntax Selector
+===============
+
+.. warning::
+
+    Try syntax is antiquated and hard to understand. If you aren't already
+    familiar with try syntax, you might want to use the ``fuzzy`` selector
+    instead.
+
+Try syntax is a command line string that goes into the commit message. Using
+``mach try syntax`` will automatically create a temporary commit with your
+chosen syntax and then delete it again after pushing to try.
+
+Try syntax can contain all kinds of different options parsed by various
+places in various repos, but the majority are parsed by `try_option_syntax.py`_.
+The most common arguments include:
+
+    * ``-b/--build`` - One of ``d``, ``o`` or ``do``. This is the build type,
+      either opt, debug or both (required).
+    * ``-p/--platform`` - The platforms you want to build and/or run tests on
+      (required).
+    * ``-u/--unittests`` - The test tasks you want to run (optional).
+    * ``-t/--talos`` - The talos tasks you want to run (optional).
+
+Here are some examples:
+
+.. code-block:: shell
+
+    $ mach try syntax -b do -p linux,macosx64 -u mochitest-e10s-1,crashtest -t none
+    $ mach try syntax -b d -p win64 -u all
+    $ mach try syntax -b o -p linux64
+
+Unfortunately, knowing the magic strings that make it work can be a bit of a
+guessing game. If you are unsure of what string will get your task to run, try
+using :doc:`mach try fuzzy <fuzzy>` instead.
+
+While using ``mach try syntax -b do -p all -u all -t all`` will work, heavy use
+of ``all`` is discouraged as it consumes a lot of unnecessary resources (some of
+which are hardware constrained).
+
+..  _try_option_syntax.py: https://searchfox.org/mozilla-central/source/taskcluster/gecko_taskgraph/try_option_syntax.py
diff --git a/tools/tryselect/docs/tasks.rst b/tools/tryselect/docs/tasks.rst
new file mode 100644
index 0000000000..61de9ec9ed
--- /dev/null
+++ b/tools/tryselect/docs/tasks.rst
@@ -0,0 +1,152 @@
+Task Generation
+===============
+
+Many selectors (including ``chooser``, ``coverage`` and ``fuzzy``) source their available tasks
+directly from the :ref:`taskgraph <TaskCluster Task-Graph Generation>` module by building the taskgraph
+locally. This means that the list of available tasks will never be stale. While this is very
+powerful, it comes with a large enough performance cost to get annoying (around twenty seconds).
+
+The result of the taskgraph generation will be cached, so this penalty will only be incurred
+whenever a file in the ``/taskcluster`` directory is modified. Unfortunately this directory changes
+pretty frequently, so developers can expect to rebuild the cache each time they pull in
+``mozilla-central``. Developers who regularly work on ``/taskcluster`` can expect to rebuild even
+more frequently.
+
+
+Configuring Watchman
+--------------------
+
+It's possible to bypass this penalty completely by using the file watching service `watchman`_. If
+you use the ``fsmonitor`` mercurial extension, you already have ``watchman`` installed.
+
+.. note::
+
+    If you aren't using `fsmonitor`_ but end up installng watchman anyway, you
+    might as well enable it for a faster Mercurial experience.
+
+Otherwise, `install watchman`_. If using Linux you'll likely run into the `inotify limits`_ outlined
+on that page due to the size of ``mozilla-central``. You can `read this page`_ for more information
+on how to bump the limits permanently.
+
+Next run the following commands:
+
+.. code-block:: shell
+
+    $ cd path/to/mozilla-central
+    $ watchman watch .
+    $ watchman -j < tools/tryselect/watchman.json
+
+You should see output like:
+
+.. code-block:: json
+
+    {
+        "triggerid": "rebuild-taskgraph-cache",
+        "disposition": "created",
+        "version": "20200920.192359.0"
+    }
+
+That's it. Now anytime a file under ``/taskcluster`` is modified (either by your editor, or by
+updating version control), the taskgraph cache will be rebuilt in the background, allowing you to
+skip the wait the next time you run ``mach try``.
+
+.. note::
+
+    Watchman triggers are persistent and don't need to be added more than once.
+    See `Managing Triggers`_ for how to remove a trigger.
+
+You can test that everything is working by running these commands:
+
+.. code-block:: shell
+
+    $ statedir=`mach python -c "from mach.util import get_state_dir; print(get_state_dir(specific_to_topsrcdir=True))"`
+    $ rm -rf $statedir/cache/taskgraph
+    $ touch taskcluster/mach_commands.py
+    # wait a minute for generation to trigger and finish
+    $ ls $statedir/cache/taskgraph
+
+If the ``target_task_set`` file exists, you are good to go. If not you can look at the ``watchman``
+log to see if there were any errors. This typically lives somewhere like
+``/usr/local/var/run/watchman/$USER-state/log``. In this case please file a bug under ``Firefox
+Build System :: Try`` and include the relevant portion of the log.
+
+
+Running Watchman on Startup
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Watchman is both a client and a service all in one. When running a ``watchman`` command, the client
+binary will start the service in the background if it isn't running. This means on reboot the
+service won't be running and you'll need to start the service each time by invoking the client
+binary (e.g by running ``watchman version``).
+
+If you'd like this to happen automatically, you can use your favourite platform specific way of
+running commands at startup (``crontab``, ``rc.local``, etc.). Watchman stores separate state for
+each user, so be sure you run the command as the user that set up the triggers.
+
+Setting up a systemd Service
+++++++++++++++++++++++++++++
+
+If ``systemd`` is an option you can create a service:
+
+.. code-block:: ini
+
+    [Unit]
+    Description=Watchman for %i
+    After=network.target
+
+    [Service]
+    Type=simple
+    User=%i
+    ExecStart=/usr/local/bin/watchman --log-level 1 watch-list -f
+    ExecStop=/usr/local/bin/watchman shutdown-server
+
+    [Install]
+    WantedBy=multi-user.target
+
+Save this to a file called ``/etc/systemd/system/watchman@.service``. Then run:
+
+.. code-block:: shell
+
+    $ sudo systemctl enable watchman@$USER.service
+    $ sudo systemctl start watchman@$USER.service
+
+The next time you reboot, the watchman service should start automatically.
+
+
+Managing Triggers
+~~~~~~~~~~~~~~~~~
+
+When adding a trigger watchman writes it to disk. Typically it'll be a path similar to
+``/usr/local/var/run/watchman/$USER-state/state``. While editing that file by hand would work, the
+watchman binary provides an interface for managing your triggers.
+
+To see all directories you are currently watching:
+
+.. code-block:: shell
+
+    $ watchman watch-list
+
+To view triggers that are active in a specified watch:
+
+.. code-block:: shell
+
+    $ watchman trigger-list <path>
+
+To delete a trigger from a specified watch:
+
+.. code-block:: shell
+
+    $ watchman trigger-del <path> <name>
+
+In the above two examples, replace ``<path>`` with the path of the watch, presumably
+``mozilla-central``. Using ``.`` works as well if that is already your working directory. For more
+information on managing triggers and a reference of other commands, see the `official docs`_.
+
+
+.. _watchman: https://facebook.github.io/watchman/
+.. _fsmonitor: https://www.mercurial-scm.org/wiki/FsMonitorExtension
+.. _install watchman: https://facebook.github.io/watchman/docs/install.html
+.. _inotify limits: https://facebook.github.io/watchman/docs/install.html#linux-inotify-limits
+.. _read this page: https://github.com/guard/listen/wiki/Increasing-the-amount-of-inotify-watchers
+.. _this hint: https://github.com/facebook/watchman/commit/2985377eaf8c8538b28fae9add061b67991a87c2
+.. _official docs: https://facebook.github.io/watchman/docs/cmd/trigger.html
diff --git a/tools/tryselect/mach_commands.py b/tools/tryselect/mach_commands.py
new file mode 100644
index 0000000000..26c15a0990
--- /dev/null
+++ b/tools/tryselect/mach_commands.py
@@ -0,0 +1,528 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+import argparse
+import importlib
+import os
+import sys
+
+from mach.decorators import Command, SettingsProvider, SubCommand
+from mach.util import get_state_dir
+from mozbuild.base import BuildEnvironmentNotFoundException
+from mozbuild.util import memoize
+
+CONFIG_ENVIRONMENT_NOT_FOUND = """
+No config environment detected. This means we are unable to properly
+detect test files in the specified paths or tags. Please run:
+
+    $ mach configure
+
+and try again.
+""".lstrip()
+
+
+class get_parser:
+    def __init__(self, selector):
+        self.selector = selector
+
+    def __call__(self):
+        mod = importlib.import_module("tryselect.selectors.{}".format(self.selector))
+        return getattr(mod, "{}Parser".format(self.selector.capitalize()))()
+
+
+def generic_parser():
+    from tryselect.cli import BaseTryParser
+
+    parser = BaseTryParser()
+    parser.add_argument("argv", nargs=argparse.REMAINDER)
+    return parser
+
+
+@SettingsProvider
+class TryConfig:
+    @classmethod
+    def config_settings(cls):
+        from mach.registrar import Registrar
+
+        desc = (
+            "The default selector to use when running `mach try` without a subcommand."
+        )
+        choices = Registrar.command_handlers["try"].subcommand_handlers.keys()
+
+        return [
+            ("try.default", "string", desc, "auto", {"choices": choices}),
+            (
+                "try.maxhistory",
+                "int",
+                "Maximum number of pushes to save in history.",
+                10,
+            ),
+        ]
+
+
+def init(command_context):
+    from tryselect import push
+
+    push.MAX_HISTORY = command_context._mach_context.settings["try"]["maxhistory"]
+
+
+@memoize
+def presets(command_context):
+    from tryselect.preset import MergedHandler
+
+    # Create our handler using both local and in-tree presets. The first
+    # path in this list will be treated as the 'user' file for the purposes
+    # of saving and editing. All subsequent paths are 'read-only'. We check
+    # an environment variable first for testing purposes.
+    if os.environ.get("MACH_TRY_PRESET_PATHS"):
+        preset_paths = os.environ["MACH_TRY_PRESET_PATHS"].split(os.pathsep)
+    else:
+        preset_paths = [
+            os.path.join(get_state_dir(), "try_presets.yml"),
+            os.path.join(
+                command_context.topsrcdir, "tools", "tryselect", "try_presets.yml"
+            ),
+        ]
+
+    return MergedHandler(*preset_paths)
+
+
+def handle_presets(
+    command_context, preset_action=None, save=None, preset=None, **kwargs
+):
+    """Handle preset related arguments.
+
+    This logic lives here so that the underlying selectors don't need
+    special preset handling. They can all save and load presets the same
+    way.
+    """
+    from tryselect.util.dicttools import merge
+
+    user_presets = presets(command_context).handlers[0]
+    if preset_action == "list":
+        presets(command_context).list()
+        sys.exit()
+
+    if preset_action == "edit":
+        user_presets.edit()
+        sys.exit()
+
+    parser = command_context._mach_context.handler.parser
+    subcommand = command_context._mach_context.handler.subcommand
+    if "preset" not in parser.common_groups:
+        return kwargs
+
+    default = parser.get_default
+    if save:
+        selector = (
+            subcommand or command_context._mach_context.settings["try"]["default"]
+        )
+
+        # Only save non-default values for simplicity.
+        kwargs = {k: v for k, v in kwargs.items() if v != default(k)}
+        user_presets.save(save, selector=selector, **kwargs)
+        print("preset saved, run with: --preset={}".format(save))
+        sys.exit()
+
+    if preset:
+        if preset not in presets(command_context):
+            command_context._mach_context.parser.error(
+                "preset '{}' does not exist".format(preset)
+            )
+
+        name = preset
+        preset = presets(command_context)[name]
+        selector = preset.pop("selector")
+        preset.pop("description", None)  # description isn't used by any selectors
+
+        if not subcommand:
+            subcommand = selector
+        elif subcommand != selector:
+            print(
+                "error: preset '{}' exists for a different selector "
+                "(did you mean to run 'mach try {}' instead?)".format(name, selector)
+            )
+            sys.exit(1)
+
+        # Order of precedence is defaults -> presets -> cli. Configuration
+        # from the right overwrites configuration from the left.
+        defaults = {}
+        nondefaults = {}
+        for k, v in kwargs.items():
+            if v == default(k):
+                defaults[k] = v
+            else:
+                nondefaults[k] = v
+
+        kwargs = merge(defaults, preset, nondefaults)
+
+    return kwargs
+
+
+def handle_try_config(command_context, **kwargs):
+    from tryselect.util.dicttools import merge
+
+    to_validate = []
+    kwargs.setdefault("try_config", {})
+    for cls in command_context._mach_context.handler.parser.task_configs.values():
+        try_config = cls.try_config(**kwargs)
+        if try_config is not None:
+            to_validate.append(cls)
+            kwargs["try_config"] = merge(kwargs["try_config"], try_config)
+
+        for name in cls.dests:
+            del kwargs[name]
+
+    # Validate task_configs after they have all been parsed to avoid
+    # depending on the order they were processed.
+    for cls in to_validate:
+        cls.validate(**kwargs)
+    return kwargs
+
+
+def run(command_context, **kwargs):
+    kwargs = handle_presets(command_context, **kwargs)
+
+    if command_context._mach_context.handler.parser.task_configs:
+        kwargs = handle_try_config(command_context, **kwargs)
+
+    mod = importlib.import_module(
+        "tryselect.selectors.{}".format(
+            command_context._mach_context.handler.subcommand
+        )
+    )
+    return mod.run(**kwargs)
+
+
+@Command(
+    "try",
+    category="ci",
+    description="Push selected tasks to the try server",
+    parser=generic_parser,
+)
+def try_default(command_context, argv=None, **kwargs):
+    """Push selected tests to the try server.
+
+    The |mach try| command is a frontend for scheduling tasks to
+    run on try server using selectors. A selector is a subcommand
+    that provides its own set of command line arguments and are
+    listed below.
+
+    If no subcommand is specified, the `auto` selector is run by
+    default. Run |mach try auto --help| for more information on
+    scheduling with the `auto` selector.
+    """
+    init(command_context)
+    subcommand = command_context._mach_context.handler.subcommand
+    # We do special handling of presets here so that `./mach try --preset foo`
+    # works no matter what subcommand 'foo' was saved with.
+    preset = kwargs["preset"]
+    if preset:
+        if preset not in presets(command_context):
+            command_context._mach_context.handler.parser.error(
+                "preset '{}' does not exist".format(preset)
+            )
+
+        subcommand = presets(command_context)[preset]["selector"]
+
+    sub = subcommand or command_context._mach_context.settings["try"]["default"]
+    return command_context._mach_context.commands.dispatch(
+        "try", command_context._mach_context, subcommand=sub, argv=argv, **kwargs
+    )
+
+
+@SubCommand(
+    "try",
+    "fuzzy",
+    description="Select tasks on try using a fuzzy finder",
+    parser=get_parser("fuzzy"),
+)
+def try_fuzzy(command_context, **kwargs):
+    """Select which tasks to run with a fuzzy finding interface (fzf).
+
+    When entering the fzf interface you'll be confronted by two panes. The
+    one on the left contains every possible task you can schedule, the one
+    on the right contains the list of selected tasks. In other words, the
+    tasks that will be scheduled once you you press <enter>.
+
+    At first fzf will automatically select whichever task is under your
+    cursor, which simplifies the case when you are looking for a single
+    task. But normally you'll want to select many tasks. To accomplish
+    you'll generally start by typing a query in the search bar to filter
+    down the list of tasks (see Extended Search below). Then you'll either:
+
+    A) Move the cursor to each task you want and press <tab> to select it.
+    Notice it now shows up in the pane to the right.
+
+    OR
+
+    B) Press <ctrl-a> to select every task that matches your filter.
+
+    You can delete your query, type a new one and select further tasks as
+    many times as you like. Once you are happy with your selection, press
+    <enter> to push the selected tasks to try.
+
+    All selected task labels and their dependencies will be scheduled. This
+    means you can select a test task and its build will automatically be
+    filled in.
+
+
+    Keyboard Shortcuts
+    ------------------
+
+    When in the fuzzy finder interface, start typing to filter down the
+    task list. Then use the following keyboard shortcuts to select tasks:
+
+      Ctrl-K / Up    => Move cursor up
+      Ctrl-J / Down  => Move cursor down
+      Tab            => Select task + move cursor down
+      Shift-Tab      => Select task + move cursor up
+      Ctrl-A         => Select all currently filtered tasks
+      Ctrl-D         => De-select all currently filtered tasks
+      Ctrl-T         => Toggle select all currently filtered tasks
+      Alt-Bspace     => Clear query from input bar
+      Enter          => Accept selection and exit
+      Ctrl-C / Esc   => Cancel selection and exit
+      ?              => Toggle preview pane
+
+    There are many more shortcuts enabled by default, you can also define
+    your own shortcuts by setting `--bind` in the $FZF_DEFAULT_OPTS
+    environment variable. See `man fzf` for more info.
+
+
+    Extended Search
+    ---------------
+
+    When typing in search terms, the following modifiers can be applied:
+
+      'word: exact match (line must contain the literal string "word")
+      ^word: exact prefix match (line must start with literal "word")
+      word$: exact suffix match (line must end with literal "word")
+      !word: exact negation match (line must not contain literal "word")
+      'a | 'b: OR operator (joins two exact match operators together)
+
+    For example:
+
+      ^start 'exact | !ignore fuzzy end$
+
+
+    Documentation
+    -------------
+
+    For more detailed documentation, please see:
+    https://firefox-source-docs.mozilla.org/tools/try/selectors/fuzzy.html
+    """
+    init(command_context)
+    if kwargs.pop("interactive"):
+        kwargs["query"].append("INTERACTIVE")
+
+    if kwargs.pop("intersection"):
+        kwargs["intersect_query"] = kwargs["query"]
+        del kwargs["query"]
+
+    if kwargs.get("save") and not kwargs.get("query"):
+        # If saving preset without -q/--query, allow user to use the
+        # interface to build the query.
+        kwargs_copy = kwargs.copy()
+        kwargs_copy["dry_run"] = True
+        kwargs_copy["save"] = None
+        kwargs["query"] = run(command_context, save_query=True, **kwargs_copy)
+        if not kwargs["query"]:
+            return
+
+    if kwargs.get("paths"):
+        kwargs["test_paths"] = kwargs["paths"]
+
+    return run(command_context, **kwargs)
+
+
+@SubCommand(
+    "try",
+    "chooser",
+    description="Schedule tasks by selecting them from a web interface.",
+    parser=get_parser("chooser"),
+)
+def try_chooser(command_context, **kwargs):
+    """Push tasks selected from a web interface to try.
+
+    This selector will build the taskgraph and spin up a dynamically
+    created 'trychooser-like' web-page on the localhost. After a selection
+    has been made, pressing the 'Push' button will automatically push the
+    selection to try.
+    """
+    init(command_context)
+    command_context.activate_virtualenv()
+    path = os.path.join(
+        "tools", "tryselect", "selectors", "chooser", "requirements.txt"
+    )
+    command_context.virtualenv_manager.install_pip_requirements(path, quiet=True)
+
+    return run(command_context, **kwargs)
+
+
+@SubCommand(
+    "try",
+    "auto",
+    description="Automatically determine which tasks to run. This runs the same "
+    "set of tasks that would be run on autoland. This "
+    "selector is EXPERIMENTAL.",
+    parser=get_parser("auto"),
+)
+def try_auto(command_context, **kwargs):
+    init(command_context)
+    return run(command_context, **kwargs)
+
+
+@SubCommand(
+    "try",
+    "again",
+    description="Schedule a previously generated (non try syntax) push again.",
+    parser=get_parser("again"),
+)
+def try_again(command_context, **kwargs):
+    init(command_context)
+    return run(command_context, **kwargs)
+
+
+@SubCommand(
+    "try",
+    "empty",
+    description="Push to try without scheduling any tasks.",
+    parser=get_parser("empty"),
+)
+def try_empty(command_context, **kwargs):
+    """Push to try, running no builds or tests
+
+    This selector does not prompt you to run anything, it just pushes
+    your patches to try, running no builds or tests by default. After
+    the push finishes, you can manually add desired jobs to your push
+    via Treeherder's Add New Jobs feature, located in the per-push
+    menu.
+    """
+    init(command_context)
+    return run(command_context, **kwargs)
+
+
+@SubCommand(
+    "try",
+    "syntax",
+    description="Select tasks on try using try syntax",
+    parser=get_parser("syntax"),
+)
+def try_syntax(command_context, **kwargs):
+    """Push the current tree to try, with the specified syntax.
+
+    Build options, platforms and regression tests may be selected
+    using the usual try options (-b, -p and -u respectively). In
+    addition, tests in a given directory may be automatically
+    selected by passing that directory as a positional argument to the
+    command. For example:
+
+    mach try -b d -p linux64 dom testing/web-platform/tests/dom
+
+    would schedule a try run for linux64 debug consisting of all
+    tests under dom/ and testing/web-platform/tests/dom.
+
+    Test selection using positional arguments is available for
+    mochitests, reftests, xpcshell tests and web-platform-tests.
+
+    Tests may be also filtered by passing --tag to the command,
+    which will run only tests marked as having the specified
+    tags e.g.
+
+    mach try -b d -p win64 --tag media
+
+    would run all tests tagged 'media' on Windows 64.
+
+    If both positional arguments or tags and -u are supplied, the
+    suites in -u will be run in full. Where tests are selected by
+    positional argument they will be run in a single chunk.
+
+    If no build option is selected, both debug and opt will be
+    scheduled. If no platform is selected a default is taken from
+    the AUTOTRY_PLATFORM_HINT environment variable, if set.
+
+    The command requires either its own mercurial extension ("push-to-try",
+    installable from mach vcs-setup) or a git repo using git-cinnabar
+    (installable from mach vcs-setup).
+
+    """
+    init(command_context)
+    try:
+        if command_context.substs.get("MOZ_ARTIFACT_BUILDS"):
+            kwargs["local_artifact_build"] = True
+    except BuildEnvironmentNotFoundException:
+        # If we don't have a build locally, we can't tell whether
+        # an artifact build is desired, but we still want the
+        # command to succeed, if possible.
+        pass
+
+    config_status = os.path.join(command_context.topobjdir, "config.status")
+    if (kwargs["paths"] or kwargs["tags"]) and not config_status:
+        print(CONFIG_ENVIRONMENT_NOT_FOUND)
+        sys.exit(1)
+
+    return run(command_context, **kwargs)
+
+
+@SubCommand(
+    "try",
+    "coverage",
+    description="Select tasks on try using coverage data",
+    parser=get_parser("coverage"),
+)
+def try_coverage(command_context, **kwargs):
+    """Select which tasks to use using coverage data."""
+    init(command_context)
+    return run(command_context, **kwargs)
+
+
+@SubCommand(
+    "try",
+    "release",
+    description="Push the current tree to try, configured for a staging release.",
+    parser=get_parser("release"),
+)
+def try_release(command_context, **kwargs):
+    """Push the current tree to try, configured for a staging release."""
+    init(command_context)
+    return run(command_context, **kwargs)
+
+
+@SubCommand(
+    "try",
+    "scriptworker",
+    description="Run scriptworker tasks against a recent release.",
+    parser=get_parser("scriptworker"),
+)
+def try_scriptworker(command_context, **kwargs):
+    """Run scriptworker tasks against a recent release.
+
+    Requires VPN and shipit access.
+    """
+    init(command_context)
+    return run(command_context, **kwargs)
+
+
+@SubCommand(
+    "try",
+    "compare",
+    description="Push two try jobs, one on your current commit and another on the one you specify",
+    parser=get_parser("compare"),
+)
+def try_compare(command_context, **kwargs):
+    init(command_context)
+    return run(command_context, **kwargs)
+
+
+@SubCommand(
+    "try",
+    "perf",
+    description="Try selector for running performance tests.",
+    parser=get_parser("perf"),
+)
+def try_perf(command_context, **kwargs):
+    init(command_context)
+    return run(command_context, **kwargs)
diff --git a/tools/tryselect/preset.py b/tools/tryselect/preset.py
new file mode 100644
index 0000000000..98d2849a71
--- /dev/null
+++ b/tools/tryselect/preset.py
@@ -0,0 +1,97 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+import os
+import shlex
+import subprocess
+
+import yaml
+
+
+class PresetHandler:
+    def __init__(self, path):
+        self.path = path
+        self._presets = {}
+
+    @property
+    def presets(self):
+        if not self._presets and os.path.isfile(self.path):
+            with open(self.path) as fh:
+                self._presets = yaml.safe_load(fh) or {}
+
+        return self._presets
+
+    def __contains__(self, name):
+        return name in self.presets
+
+    def __getitem__(self, name):
+        return self.presets[name]
+
+    def __len__(self):
+        return len(self.presets)
+
+    def __str__(self):
+        if not self.presets:
+            return ""
+        return yaml.safe_dump(self.presets, default_flow_style=False)
+
+    def list(self):
+        if not self.presets:
+            print("no presets found")
+        else:
+            print(self)
+
+    def edit(self):
+        if "EDITOR" not in os.environ:
+            print(
+                "error: must set the $EDITOR environment variable to use --edit-presets"
+            )
+            return
+
+        subprocess.call(shlex.split(os.environ["EDITOR"]) + [self.path])
+
+    def save(self, name, **data):
+        self.presets[name] = data
+
+        with open(self.path, "w") as fh:
+            fh.write(str(self))
+
+
+class MergedHandler:
+    def __init__(self, *paths):
+        """Helper class for dealing with multiple preset files."""
+        self.handlers = [PresetHandler(p) for p in paths]
+
+    def __contains__(self, name):
+        return any(name in handler for handler in self.handlers)
+
+    def __getitem__(self, name):
+        for handler in self.handlers:
+            if name in handler:
+                return handler[name]
+        raise KeyError(name)
+
+    def __len__(self):
+        return sum(len(h) for h in self.handlers)
+
+    def __str__(self):
+        all_presets = {
+            k: v for handler in self.handlers for k, v in handler.presets.items()
+        }
+        return yaml.safe_dump(all_presets, default_flow_style=False)
+
+    def list(self):
+        if len(self) == 0:
+            print("no presets found")
+            return
+
+        for handler in self.handlers:
+            val = str(handler)
+            if val:
+                val = "\n  ".join(
+                    [""] + val.splitlines() + [""]
+                )  # indent all lines by 2 spaces
+                print("Presets from {}:".format(handler.path))
+                print(val)
diff --git a/tools/tryselect/push.py b/tools/tryselect/push.py
new file mode 100644
index 0000000000..cade05db9b
--- /dev/null
+++ b/tools/tryselect/push.py
@@ -0,0 +1,239 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+import json
+import os
+import sys
+import traceback
+
+import six
+from mach.util import get_state_dir
+from mozbuild.base import MozbuildObject
+from mozversioncontrol import MissingVCSExtension, get_repository_object
+
+from .util.estimates import duration_summary
+from .util.manage_estimates import (
+    download_task_history_data,
+    make_trimmed_taskgraph_cache,
+)
+
+GIT_CINNABAR_NOT_FOUND = """
+Could not detect `git-cinnabar`.
+
+The `mach try` command requires git-cinnabar to be installed when
+pushing from git. Please install it by running:
+
+    $ ./mach vcs-setup
+""".lstrip()
+
+HG_PUSH_TO_TRY_NOT_FOUND = """
+Could not detect `push-to-try`.
+
+The `mach try` command requires the push-to-try extension enabled
+when pushing from hg. Please install it by running:
+
+    $ ./mach vcs-setup
+""".lstrip()
+
+VCS_NOT_FOUND = """
+Could not detect version control. Only `hg` or `git` are supported.
+""".strip()
+
+UNCOMMITTED_CHANGES = """
+ERROR please commit changes before continuing
+""".strip()
+
+MAX_HISTORY = 10
+
+here = os.path.abspath(os.path.dirname(__file__))
+build = MozbuildObject.from_environment(cwd=here)
+vcs = get_repository_object(build.topsrcdir)
+
+history_path = os.path.join(
+    get_state_dir(specific_to_topsrcdir=True), "history", "try_task_configs.json"
+)
+
+
+def write_task_config(try_task_config):
+    config_path = os.path.join(vcs.path, "try_task_config.json")
+    with open(config_path, "w") as fh:
+        json.dump(try_task_config, fh, indent=4, separators=(",", ": "), sort_keys=True)
+        fh.write("\n")
+    return config_path
+
+
+def write_task_config_history(msg, try_task_config):
+    if not os.path.isfile(history_path):
+        if not os.path.isdir(os.path.dirname(history_path)):
+            os.makedirs(os.path.dirname(history_path))
+        history = []
+    else:
+        with open(history_path) as fh:
+            history = fh.read().strip().splitlines()
+
+    history.insert(0, json.dumps([msg, try_task_config]))
+    history = history[:MAX_HISTORY]
+    with open(history_path, "w") as fh:
+        fh.write("\n".join(history))
+
+
+def check_working_directory(push=True):
+    if not push:
+        return
+
+    if not vcs.working_directory_clean():
+        print(UNCOMMITTED_CHANGES)
+        sys.exit(1)
+
+
+def generate_try_task_config(method, labels, try_config=None, routes=None):
+    try_task_config = try_config or {}
+    try_task_config.setdefault("env", {})["TRY_SELECTOR"] = method
+    try_task_config.update(
+        {
+            "version": 1,
+            "tasks": sorted(labels),
+        }
+    )
+    if routes:
+        try_task_config["routes"] = routes
+
+    return try_task_config
+
+
+def task_labels_from_try_config(try_task_config):
+    if try_task_config["version"] == 2:
+        parameters = try_task_config.get("parameters", {})
+        if parameters.get("try_mode") == "try_task_config":
+            return parameters["try_task_config"]["tasks"]
+        else:
+            return None
+    elif try_task_config["version"] == 1:
+        return try_task_config.get("tasks", list())
+    else:
+        return None
+
+
+def display_push_estimates(try_task_config):
+    task_labels = task_labels_from_try_config(try_task_config)
+    if task_labels is None:
+        return
+
+    cache_dir = os.path.join(
+        get_state_dir(specific_to_topsrcdir=True), "cache", "taskgraph"
+    )
+
+    graph_cache = None
+    dep_cache = None
+    target_file = None
+    for graph_cache_file in ["target_task_graph", "full_task_graph"]:
+        graph_cache = os.path.join(cache_dir, graph_cache_file)
+        if os.path.isfile(graph_cache):
+            dep_cache = graph_cache.replace("task_graph", "task_dependencies")
+            target_file = graph_cache.replace("task_graph", "task_set")
+            break
+
+    if not dep_cache:
+        return
+
+    download_task_history_data(cache_dir=cache_dir)
+    make_trimmed_taskgraph_cache(graph_cache, dep_cache, target_file=target_file)
+
+    durations = duration_summary(dep_cache, task_labels, cache_dir)
+
+    print(
+        "estimates: Runs {} tasks ({} selected, {} dependencies)".format(
+            durations["dependency_count"] + durations["selected_count"],
+            durations["selected_count"],
+            durations["dependency_count"],
+        )
+    )
+    print(
+        "estimates: Total task duration {}".format(
+            durations["dependency_duration"] + durations["selected_duration"]
+        )
+    )
+    if "percentile" in durations:
+        print(
+            "estimates: In the top {}% of durations".format(
+                100 - durations["percentile"]
+            )
+        )
+    print(
+        "estimates: Should take about {} (Finished around {})".format(
+            durations["wall_duration_seconds"],
+            durations["eta_datetime"].strftime("%Y-%m-%d %H:%M"),
+        )
+    )
+
+
+def push_to_try(
+    method,
+    msg,
+    try_task_config=None,
+    stage_changes=False,
+    dry_run=False,
+    closed_tree=False,
+    files_to_change=None,
+    allow_log_capture=False,
+):
+    push = not stage_changes and not dry_run
+    check_working_directory(push)
+
+    if try_task_config and method not in ("auto", "empty"):
+        try:
+            display_push_estimates(try_task_config)
+        except Exception:
+            traceback.print_exc()
+            print("warning: unable to display push estimates")
+
+    # Format the commit message
+    closed_tree_string = " ON A CLOSED TREE" if closed_tree else ""
+    commit_message = "{}{}\n\nPushed via `mach try {}`".format(
+        msg,
+        closed_tree_string,
+        method,
+    )
+
+    config_path = None
+    changed_files = []
+    if try_task_config:
+        if push and method not in ("again", "auto", "empty"):
+            write_task_config_history(msg, try_task_config)
+        config_path = write_task_config(try_task_config)
+        changed_files.append(config_path)
+
+    if (push or stage_changes) and files_to_change:
+        for path, content in files_to_change.items():
+            path = os.path.join(vcs.path, path)
+            with open(path, "wb") as fh:
+                fh.write(six.ensure_binary(content))
+            changed_files.append(path)
+
+    try:
+        if not push:
+            print("Commit message:")
+            print(commit_message)
+            if config_path:
+                print("Calculated try_task_config.json:")
+                with open(config_path) as fh:
+                    print(fh.read())
+            return
+
+        vcs.add_remove_files(*changed_files)
+
+        try:
+            vcs.push_to_try(commit_message, allow_log_capture=allow_log_capture)
+        except MissingVCSExtension as e:
+            if e.ext == "push-to-try":
+                print(HG_PUSH_TO_TRY_NOT_FOUND)
+            elif e.ext == "cinnabar":
+                print(GIT_CINNABAR_NOT_FOUND)
+            else:
+                raise
+            sys.exit(1)
+    finally:
+        if config_path and os.path.isfile(config_path):
+            os.remove(config_path)
diff --git a/tools/tryselect/selectors/__init__.py b/tools/tryselect/selectors/__init__.py
new file mode 100644
index 0000000000..c580d191c1
--- /dev/null
+++ b/tools/tryselect/selectors/__init__.py
@@ -0,0 +1,3 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
diff --git a/tools/tryselect/selectors/again.py b/tools/tryselect/selectors/again.py
new file mode 100644
index 0000000000..434aed7cc1
--- /dev/null
+++ b/tools/tryselect/selectors/again.py
@@ -0,0 +1,151 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+import json
+import os
+
+from ..cli import BaseTryParser
+from ..push import history_path, push_to_try
+
+
+class AgainParser(BaseTryParser):
+    name = "again"
+    arguments = [
+        [
+            ["--index"],
+            {
+                "default": 0,
+                "const": "list",
+                "nargs": "?",
+                "help": "Index of entry in the history to re-push, "
+                "where '0' is the most recent (default 0). "
+                "Use --index without a value to display indices.",
+            },
+        ],
+        [
+            ["--list"],
+            {
+                "default": False,
+                "action": "store_true",
+                "dest": "list_configs",
+                "help": "Display history and exit",
+            },
+        ],
+        [
+            ["--list-tasks"],
+            {
+                "default": 0,
+                "action": "count",
+                "dest": "list_tasks",
+                "help": "Like --list, but display selected tasks  "
+                "for each history entry, up to 10. Repeat "
+                "to display all selected tasks.",
+            },
+        ],
+        [
+            ["--purge"],
+            {
+                "default": False,
+                "action": "store_true",
+                "help": "Remove all history and exit",
+            },
+        ],
+    ]
+    common_groups = ["push"]
+
+
+def run(
+    index=0, purge=False, list_configs=False, list_tasks=0, message="{msg}", **pushargs
+):
+    if index == "list":
+        list_configs = True
+    else:
+        try:
+            index = int(index)
+        except ValueError:
+            print("error: '--index' must be an integer")
+            return 1
+
+    if purge:
+        os.remove(history_path)
+        return
+
+    if not os.path.isfile(history_path):
+        print("error: history file not found: {}".format(history_path))
+        return 1
+
+    with open(history_path) as fh:
+        history = fh.readlines()
+
+    if list_configs or list_tasks > 0:
+        for i, data in enumerate(history):
+            msg, config = json.loads(data)
+            version = config.get("version", "1")
+            settings = {}
+            if version == 1:
+                tasks = config["tasks"]
+                settings = config
+            elif version == 2:
+                try_config = config.get("parameters", {}).get("try_task_config", {})
+                tasks = try_config.get("tasks")
+            else:
+                tasks = None
+
+            if tasks is not None:
+                # Select only the things that are of interest to display.
+                settings = settings.copy()
+                env = settings.pop("env", {}).copy()
+                env.pop("TRY_SELECTOR", None)
+                for name in ("tasks", "version"):
+                    settings.pop(name, None)
+
+                def pluralize(n, noun):
+                    return "{n} {noun}{s}".format(
+                        n=n, noun=noun, s="" if n == 1 else "s"
+                    )
+
+                out = str(i) + ". (" + pluralize(len(tasks), "task")
+                if env:
+                    out += ", " + pluralize(len(env), "env var")
+                if settings:
+                    out += ", " + pluralize(len(settings), "setting")
+                out += ") " + msg
+                print(out)
+
+                if list_tasks > 0:
+                    indent = " " * 4
+                    if list_tasks > 1:
+                        shown_tasks = tasks
+                    else:
+                        shown_tasks = tasks[:10]
+                    print(indent + ("\n" + indent).join(shown_tasks))
+
+                    num_hidden_tasks = len(tasks) - len(shown_tasks)
+                    if num_hidden_tasks > 0:
+                        print("{}... and {} more".format(indent, num_hidden_tasks))
+
+                if list_tasks and env:
+                    for line in ("env: " + json.dumps(env, indent=2)).splitlines():
+                        print("    " + line)
+
+                if list_tasks and settings:
+                    for line in (
+                        "settings: " + json.dumps(settings, indent=2)
+                    ).splitlines():
+                        print("    " + line)
+            else:
+                print(
+                    "{index}. {msg}".format(
+                        index=i,
+                        msg=msg,
+                    )
+                )
+
+        return
+
+    msg, try_task_config = json.loads(history[index])
+    return push_to_try(
+        "again", message.format(msg=msg), try_task_config=try_task_config, **pushargs
+    )
diff --git a/tools/tryselect/selectors/auto.py b/tools/tryselect/selectors/auto.py
new file mode 100644
index 0000000000..7b27b33616
--- /dev/null
+++ b/tools/tryselect/selectors/auto.py
@@ -0,0 +1,115 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+from taskgraph.util.python_path import find_object
+
+from ..cli import BaseTryParser
+from ..push import push_to_try
+
+TRY_AUTO_PARAMETERS = {
+    "optimize_strategies": "gecko_taskgraph.optimize:tryselect.bugbug_reduced_manifests_config_selection_medium",  # noqa
+    "optimize_target_tasks": True,
+    "target_tasks_method": "try_auto",
+    "test_manifest_loader": "bugbug",
+    "try_mode": "try_auto",
+    "try_task_config": {},
+}
+
+
+class AutoParser(BaseTryParser):
+    name = "auto"
+    common_groups = ["push"]
+    task_configs = [
+        "artifact",
+        "env",
+        "chemspill-prio",
+        "disable-pgo",
+        "worker-overrides",
+    ]
+    arguments = [
+        [
+            ["--strategy"],
+            {
+                "default": None,
+                "help": "Override the default optimization strategy. Valid values "
+                "are the experimental strategies defined at the bottom of "
+                "`taskcluster/gecko_taskgraph/optimize/__init__.py`.",
+            },
+        ],
+        [
+            ["--tasks-regex"],
+            {
+                "default": [],
+                "action": "append",
+                "help": "Apply a regex filter to the tasks selected. Specifying "
+                "multiple times schedules the union of computed tasks.",
+            },
+        ],
+        [
+            ["--tasks-regex-exclude"],
+            {
+                "default": [],
+                "action": "append",
+                "help": "Apply a regex filter to the tasks selected. Specifying "
+                "multiple times excludes computed tasks matching any regex.",
+            },
+        ],
+    ]
+
+    def validate(self, args):
+        super().validate(args)
+
+        if args.strategy:
+            if ":" not in args.strategy:
+                args.strategy = "gecko_taskgraph.optimize:tryselect.{}".format(
+                    args.strategy
+                )
+
+            try:
+                obj = find_object(args.strategy)
+            except (ImportError, AttributeError):
+                self.error("invalid module path '{}'".format(args.strategy))
+
+            if not isinstance(obj, dict):
+                self.error("object at '{}' must be a dict".format(args.strategy))
+
+
+def run(
+    message="{msg}",
+    stage_changes=False,
+    dry_run=False,
+    closed_tree=False,
+    strategy=None,
+    tasks_regex=None,
+    tasks_regex_exclude=None,
+    try_config=None,
+    **ignored
+):
+    msg = message.format(msg="Tasks automatically selected.")
+
+    params = TRY_AUTO_PARAMETERS.copy()
+    if try_config:
+        params["try_task_config"] = try_config
+
+    if strategy:
+        params["optimize_strategies"] = strategy
+
+    if tasks_regex or tasks_regex_exclude:
+        params.setdefault("try_task_config", {})["tasks-regex"] = {}
+        params["try_task_config"]["tasks-regex"]["include"] = tasks_regex
+        params["try_task_config"]["tasks-regex"]["exclude"] = tasks_regex_exclude
+
+    task_config = {
+        "version": 2,
+        "parameters": params,
+    }
+    return push_to_try(
+        "auto",
+        msg,
+        try_task_config=task_config,
+        stage_changes=stage_changes,
+        dry_run=dry_run,
+        closed_tree=closed_tree,
+    )
diff --git a/tools/tryselect/selectors/chooser/.eslintrc.js b/tools/tryselect/selectors/chooser/.eslintrc.js
new file mode 100644
index 0000000000..861d6bafc2
--- /dev/null
+++ b/tools/tryselect/selectors/chooser/.eslintrc.js
@@ -0,0 +1,16 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+module.exports = {
+  env: {
+    jquery: true,
+  },
+  globals: {
+    apply: true,
+    applyChunks: true,
+    tasks: true,
+  },
+};
diff --git a/tools/tryselect/selectors/chooser/__init__.py b/tools/tryselect/selectors/chooser/__init__.py
new file mode 100644
index 0000000000..51263a1845
--- /dev/null
+++ b/tools/tryselect/selectors/chooser/__init__.py
@@ -0,0 +1,96 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import os
+import webbrowser
+from threading import Timer
+
+from gecko_taskgraph.target_tasks import filter_by_uncommon_try_tasks
+from tryselect.cli import BaseTryParser
+from tryselect.push import (
+    check_working_directory,
+    generate_try_task_config,
+    push_to_try,
+)
+from tryselect.tasks import generate_tasks
+
+here = os.path.abspath(os.path.dirname(__file__))
+
+
+class ChooserParser(BaseTryParser):
+    name = "chooser"
+    arguments = []
+    common_groups = ["push", "task"]
+    task_configs = [
+        "artifact",
+        "browsertime",
+        "chemspill-prio",
+        "disable-pgo",
+        "env",
+        "gecko-profile",
+        "path",
+        "pernosco",
+        "rebuild",
+        "worker-overrides",
+    ]
+
+
+def run(
+    update=False,
+    query=None,
+    try_config=None,
+    full=False,
+    parameters=None,
+    save=False,
+    preset=None,
+    mod_presets=False,
+    stage_changes=False,
+    dry_run=False,
+    message="{msg}",
+    closed_tree=False,
+):
+    from .app import create_application
+
+    push = not stage_changes and not dry_run
+    check_working_directory(push)
+
+    tg = generate_tasks(parameters, full)
+
+    # Remove tasks that are not to be shown unless `--full` is specified.
+    if not full:
+        blacklisted_tasks = [
+            label
+            for label in tg.tasks.keys()
+            if not filter_by_uncommon_try_tasks(label)
+        ]
+        for task in blacklisted_tasks:
+            tg.tasks.pop(task)
+
+    app = create_application(tg)
+
+    if os.environ.get("WERKZEUG_RUN_MAIN") == "true":
+        # we are in the reloader process, don't open the browser or do any try stuff
+        app.run()
+        return
+
+    # give app a second to start before opening the browser
+    url = "http://127.0.0.1:5000"
+    Timer(1, lambda: webbrowser.open(url)).start()
+    print("Starting trychooser on {}".format(url))
+    app.run()
+
+    selected = app.tasks
+    if not selected:
+        print("no tasks selected")
+        return
+
+    msg = "Try Chooser Enhanced ({} tasks selected)".format(len(selected))
+    return push_to_try(
+        "chooser",
+        message.format(msg=msg),
+        try_task_config=generate_try_task_config("chooser", selected, try_config),
+        stage_changes=stage_changes,
+        dry_run=dry_run,
+        closed_tree=closed_tree,
+    )
diff --git a/tools/tryselect/selectors/chooser/app.py b/tools/tryselect/selectors/chooser/app.py
new file mode 100644
index 0000000000..adbf6f33dd
--- /dev/null
+++ b/tools/tryselect/selectors/chooser/app.py
@@ -0,0 +1,177 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+from abc import ABCMeta, abstractproperty
+from collections import defaultdict
+
+from flask import Flask, render_template, request
+
+SECTIONS = []
+SUPPORTED_KINDS = set()
+
+
+def register_section(cls):
+    assert issubclass(cls, Section)
+    instance = cls()
+    SECTIONS.append(instance)
+    SUPPORTED_KINDS.update(instance.kind.split(","))
+
+
+class Section(object):
+    __metaclass__ = ABCMeta
+
+    @abstractproperty
+    def name(self):
+        pass
+
+    @abstractproperty
+    def kind(self):
+        pass
+
+    @abstractproperty
+    def title(self):
+        pass
+
+    @abstractproperty
+    def attrs(self):
+        pass
+
+    def contains(self, task):
+        return task.kind in self.kind.split(",")
+
+    def get_context(self, tasks):
+        labels = defaultdict(lambda: {"max_chunk": 0, "attrs": defaultdict(list)})
+
+        for task in tasks.values():
+            if not self.contains(task):
+                continue
+
+            task = task.attributes
+            label = labels[self.labelfn(task)]
+            for attr in self.attrs:
+                if attr in task and task[attr] not in label["attrs"][attr]:
+                    label["attrs"][attr].append(task[attr])
+
+                if "test_chunk" in task:
+                    label["max_chunk"] = max(
+                        label["max_chunk"], int(task["test_chunk"])
+                    )
+
+        return {
+            "name": self.name,
+            "kind": self.kind,
+            "title": self.title,
+            "labels": labels,
+        }
+
+
+@register_section
+class Platform(Section):
+    name = "platform"
+    kind = "build"
+    title = "Platforms"
+    attrs = ["build_platform"]
+
+    def labelfn(self, task):
+        return task["build_platform"]
+
+    def contains(self, task):
+        if not Section.contains(self, task):
+            return False
+
+        # android-stuff tasks aren't actual platforms
+        return task.task["tags"].get("android-stuff", False) != "true"
+
+
+@register_section
+class Test(Section):
+    name = "test"
+    kind = "test"
+    title = "Test Suites"
+    attrs = ["unittest_suite"]
+
+    def labelfn(self, task):
+        suite = task["unittest_suite"].replace(" ", "-")
+
+        if suite.endswith("-chunked"):
+            suite = suite[: -len("-chunked")]
+
+        return suite
+
+    def contains(self, task):
+        if not Section.contains(self, task):
+            return False
+        return task.attributes["unittest_suite"] not in ("raptor", "talos")
+
+
+@register_section
+class Perf(Section):
+    name = "perf"
+    kind = "test"
+    title = "Performance"
+    attrs = ["unittest_suite", "raptor_try_name", "talos_try_name"]
+
+    def labelfn(self, task):
+        suite = task["unittest_suite"]
+        label = task["{}_try_name".format(suite)]
+
+        if not label.startswith(suite):
+            label = "{}-{}".format(suite, label)
+
+        if label.endswith("-e10s"):
+            label = label[: -len("-e10s")]
+
+        return label
+
+    def contains(self, task):
+        if not Section.contains(self, task):
+            return False
+        return task.attributes["unittest_suite"] in ("raptor", "talos")
+
+
+@register_section
+class Analysis(Section):
+    name = "analysis"
+    kind = "build,static-analysis-autotest"
+    title = "Analysis"
+    attrs = ["build_platform"]
+
+    def labelfn(self, task):
+        return task["build_platform"]
+
+    def contains(self, task):
+        if not Section.contains(self, task):
+            return False
+        if task.kind == "build":
+            return task.task["tags"].get("android-stuff", False) == "true"
+        return True
+
+
+def create_application(tg):
+    tasks = {l: t for l, t in tg.tasks.items() if t.kind in SUPPORTED_KINDS}
+    sections = [s.get_context(tasks) for s in SECTIONS]
+    context = {
+        "tasks": {l: t.attributes for l, t in tasks.items()},
+        "sections": sections,
+    }
+
+    app = Flask(__name__)
+    app.env = "development"
+    app.tasks = []
+
+    @app.route("/", methods=["GET", "POST"])
+    def chooser():
+        if request.method == "GET":
+            return render_template("chooser.html", **context)
+
+        if request.form["action"] == "Push":
+            labels = request.form["selected-tasks"].splitlines()
+            app.tasks.extend(labels)
+
+        shutdown = request.environ.get("werkzeug.server.shutdown")
+        if shutdown:
+            shutdown()
+        return render_template("close.html")
+
+    return app
diff --git a/tools/tryselect/selectors/chooser/requirements.txt b/tools/tryselect/selectors/chooser/requirements.txt
new file mode 100644
index 0000000000..966eae636f
--- /dev/null
+++ b/tools/tryselect/selectors/chooser/requirements.txt
@@ -0,0 +1,44 @@
+Flask==1.1.4 \
+    --hash=sha256:0fbeb6180d383a9186d0d6ed954e0042ad9f18e0e8de088b2b419d526927d196 \
+    --hash=sha256:c34f04500f2cbbea882b1acb02002ad6fe6b7ffa64a6164577995657f50aed22
+click==7.1.2 \
+    --hash=sha256:d2b5255c7c6349bc1bd1e59e08cd12acbbd63ce649f2588755783aa94dfb6b1a \
+    --hash=sha256:dacca89f4bfadd5de3d7489b7c8a566eee0d3676333fbb50030263894c38c0dc
+Werkzeug==1.0.1 \
+    --hash=sha256:2de2a5db0baeae7b2d2664949077c2ac63fbd16d98da0ff71837f7d1dea3fd43 \
+    --hash=sha256:6c80b1e5ad3665290ea39320b91e1be1e0d5f60652b964a3070216de83d2e47c
+itsdangerous==1.1.0 \
+    --hash=sha256:321b033d07f2a4136d3ec762eac9f16a10ccd60f53c0c91af90217ace7ba1f19 \
+    --hash=sha256:b12271b2047cb23eeb98c8b5622e2e5c5e9abd9784a153e9d8ef9cb4dd09d749
+Jinja2==2.11.3 \
+    --hash=sha256:03e47ad063331dd6a3f04a43eddca8a966a26ba0c5b7207a9a9e4e08f1b29419 \
+    --hash=sha256:a6d58433de0ae800347cab1fa3043cebbabe8baa9d29e668f1c768cb87a333c6
+MarkupSafe==1.1.1 \
+    --hash=sha256:00bc623926325b26bb9605ae9eae8a215691f33cae5df11ca5424f06f2d1f473 \
+    --hash=sha256:09027a7803a62ca78792ad89403b1b7a73a01c8cb65909cd876f7fcebd79b161 \
+    --hash=sha256:09c4b7f37d6c648cb13f9230d847adf22f8171b1ccc4d5682398e77f40309235 \
+    --hash=sha256:1027c282dad077d0bae18be6794e6b6b8c91d58ed8a8d89a89d59693b9131db5 \
+    --hash=sha256:24982cc2533820871eba85ba648cd53d8623687ff11cbb805be4ff7b4c971aff \
+    --hash=sha256:29872e92839765e546828bb7754a68c418d927cd064fd4708fab9fe9c8bb116b \
+    --hash=sha256:43a55c2930bbc139570ac2452adf3d70cdbb3cfe5912c71cdce1c2c6bbd9c5d1 \
+    --hash=sha256:46c99d2de99945ec5cb54f23c8cd5689f6d7177305ebff350a58ce5f8de1669e \
+    --hash=sha256:500d4957e52ddc3351cabf489e79c91c17f6e0899158447047588650b5e69183 \
+    --hash=sha256:535f6fc4d397c1563d08b88e485c3496cf5784e927af890fb3c3aac7f933ec66 \
+    --hash=sha256:62fe6c95e3ec8a7fad637b7f3d372c15ec1caa01ab47926cfdf7a75b40e0eac1 \
+    --hash=sha256:6dd73240d2af64df90aa7c4e7481e23825ea70af4b4922f8ede5b9e35f78a3b1 \
+    --hash=sha256:717ba8fe3ae9cc0006d7c451f0bb265ee07739daf76355d06366154ee68d221e \
+    --hash=sha256:79855e1c5b8da654cf486b830bd42c06e8780cea587384cf6545b7d9ac013a0b \
+    --hash=sha256:7c1699dfe0cf8ff607dbdcc1e9b9af1755371f92a68f706051cc8c37d447c905 \
+    --hash=sha256:88e5fcfb52ee7b911e8bb6d6aa2fd21fbecc674eadd44118a9cc3863f938e735 \
+    --hash=sha256:8defac2f2ccd6805ebf65f5eeb132adcf2ab57aa11fdf4c0dd5169a004710e7d \
+    --hash=sha256:98c7086708b163d425c67c7a91bad6e466bb99d797aa64f965e9d25c12111a5e \
+    --hash=sha256:9add70b36c5666a2ed02b43b335fe19002ee5235efd4b8a89bfcf9005bebac0d \
+    --hash=sha256:9bf40443012702a1d2070043cb6291650a0841ece432556f784f004937f0f32c \
+    --hash=sha256:ade5e387d2ad0d7ebf59146cc00c8044acbd863725f887353a10df825fc8ae21 \
+    --hash=sha256:b00c1de48212e4cc9603895652c5c410df699856a2853135b3967591e4beebc2 \
+    --hash=sha256:b1282f8c00509d99fef04d8ba936b156d419be841854fe901d8ae224c59f0be5 \
+    --hash=sha256:b2051432115498d3562c084a49bba65d97cf251f5a331c64a12ee7e04dacc51b \
+    --hash=sha256:ba59edeaa2fc6114428f1637ffff42da1e311e29382d81b339c1817d37ec93c6 \
+    --hash=sha256:c8716a48d94b06bb3b2524c2b77e055fb313aeb4ea620c8dd03a105574ba704f \
+    --hash=sha256:cd5df75523866410809ca100dc9681e301e3c27567cf498077e8551b6d20e42f \
+    --hash=sha256:e249096428b3ae81b08327a63a485ad0878de3fb939049038579ac0ef61e17e7
diff --git a/tools/tryselect/selectors/chooser/static/filter.js b/tools/tryselect/selectors/chooser/static/filter.js
new file mode 100644
index 0000000000..a82ff2920d
--- /dev/null
+++ b/tools/tryselect/selectors/chooser/static/filter.js
@@ -0,0 +1,116 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+const selection = $("#selection")[0];
+const count = $("#selection-count")[0];
+const pluralize = (count, noun, suffix = "s") =>
+  `${count} ${noun}${count !== 1 ? suffix : ""}`;
+
+var selected = [];
+
+var updateLabels = () => {
+  $(".tab-pane.active > .filter-label").each(function(index) {
+    let box = $("#" + this.htmlFor)[0];
+    let method = box.checked ? "add" : "remove";
+    $(this)[method + "Class"]("is-checked");
+  });
+};
+
+var apply = () => {
+  let filters = {};
+  let kinds = [];
+
+  $(".filter:checked").each(function(index) {
+    for (let kind of this.name.split(",")) {
+      if (!kinds.includes(kind)) {
+        kinds.push(kind);
+      }
+    }
+
+    // Checkbox element values are generated by Section.get_context() in app.py
+    let attrs = JSON.parse(this.value);
+    for (let attr in attrs) {
+      if (!(attr in filters)) {
+        filters[attr] = [];
+      }
+
+      let values = attrs[attr];
+      filters[attr] = filters[attr].concat(values);
+    }
+  });
+  updateLabels();
+
+  if (
+    !Object.keys(filters).length ||
+    (Object.keys(filters).length == 1 && "build_type" in filters)
+  ) {
+    selection.value = "";
+    count.innerHTML = "0 tasks selected";
+    return;
+  }
+
+  var taskMatches = label => {
+    let task = tasks[label];
+
+    // If no box for the given kind has been checked, this task is
+    // automatically not selected.
+    if (!kinds.includes(task.kind)) {
+      return false;
+    }
+
+    for (let attr in filters) {
+      let values = filters[attr];
+      if (!(attr in task) || values.includes(task[attr])) {
+        continue;
+      }
+      return false;
+    }
+    return true;
+  };
+
+  selected = Object.keys(tasks).filter(taskMatches);
+  applyChunks();
+};
+
+var applyChunks = () => {
+  // For tasks that have a chunk filter applied, we handle that here.
+  let filters = {};
+  $(".filter:text").each(function(index) {
+    let value = $(this).val();
+    if (value === "") {
+      return;
+    }
+
+    let attrs = JSON.parse(this.name);
+    let key = `${attrs.unittest_suite}-${attrs.unittest_flavor}`;
+    if (!(key in filters)) {
+      filters[key] = [];
+    }
+
+    // Parse the chunk strings. These are formatted like printer page setups, e.g: "1,4-6,9"
+    for (let item of value.split(",")) {
+      if (!item.includes("-")) {
+        filters[key].push(parseInt(item));
+        continue;
+      }
+
+      let [start, end] = item.split("-");
+      for (let i = parseInt(start); i <= parseInt(end); ++i) {
+        filters[key].push(i);
+      }
+    }
+  });
+
+  let chunked = selected.filter(function(label) {
+    let task = tasks[label];
+    let key = task.unittest_suite + "-" + task.unittest_flavor;
+    if (key in filters && !filters[key].includes(parseInt(task.test_chunk))) {
+      return false;
+    }
+    return true;
+  });
+
+  selection.value = chunked.join("\n");
+  count.innerText = pluralize(chunked.length, "task") + " selected";
+};
diff --git a/tools/tryselect/selectors/chooser/static/select.js b/tools/tryselect/selectors/chooser/static/select.js
new file mode 100644
index 0000000000..439f979457
--- /dev/null
+++ b/tools/tryselect/selectors/chooser/static/select.js
@@ -0,0 +1,46 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+const labels = $("label.multiselect");
+const boxes = $("label.multiselect input:checkbox");
+var lastChecked = {};
+
+// implements shift+click
+labels.click(function(e) {
+  if (e.target.tagName === "INPUT") {
+    return;
+  }
+
+  let box = $("#" + this.htmlFor)[0];
+  let activeSection = $("div.tab-pane.active")[0].id;
+
+  if (activeSection in lastChecked) {
+    // Bug 559506 - In Firefox shift/ctrl/alt+clicking a label doesn't check the box.
+    let isFirefox = navigator.userAgent.toLowerCase().indexOf("firefox") > -1;
+
+    if (e.shiftKey) {
+      if (isFirefox) {
+        box.checked = !box.checked;
+      }
+
+      let start = boxes.index(box);
+      let end = boxes.index(lastChecked[activeSection]);
+
+      boxes
+        .slice(Math.min(start, end), Math.max(start, end) + 1)
+        .prop("checked", box.checked);
+      apply();
+    }
+  }
+
+  lastChecked[activeSection] = box;
+});
+
+function selectAll(btn) {
+  let checked = !!btn.value;
+  $("div.active label.filter-label").each(function(index) {
+    $(this).find("input:checkbox")[0].checked = checked;
+  });
+  apply();
+}
diff --git a/tools/tryselect/selectors/chooser/static/style.css b/tools/tryselect/selectors/chooser/static/style.css
new file mode 100644
index 0000000000..2945e4ee12
--- /dev/null
+++ b/tools/tryselect/selectors/chooser/static/style.css
@@ -0,0 +1,108 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+body {
+  padding-top: 70px;
+}
+
+/* Tabs */
+
+#tabbar .nav-link {
+  color: #009570;
+  font-size: 18px;
+  padding-bottom: 15px;
+  padding-top: 15px;
+}
+
+#tabbar .nav-link.active {
+  color: #212529;
+}
+
+#tabbar .nav-link:hover {
+  color: #0f5a3a;
+}
+
+/* Sections */
+
+.tab-content button {
+  font-size: 14px;
+  margin-bottom: 5px;
+  margin-top: 10px;
+}
+
+.filter-label {
+  display: block;
+  font-size: 16px;
+  position: relative;
+  padding-left: 15px;
+  padding-right: 15px;
+  padding-top: 10px;
+  padding-bottom: 10px;
+  margin-bottom: 0;
+  user-select: none;
+  user-select: none;
+  vertical-align: middle;
+}
+
+.filter-label span {
+  display: flex;
+  min-height: 34px;
+  align-items: center;
+  justify-content: space-between;
+}
+
+.filter-label input[type="checkbox"] {
+  position: absolute;
+  opacity: 0;
+  height: 0;
+  width: 0;
+}
+
+.filter-label input[type="text"] {
+  width: 50px;
+}
+
+.filter-label:hover {
+  background-color: #91a0b0;
+}
+
+.filter-label.is-checked:hover {
+  background-color: #91a0b0;
+}
+
+.filter-label.is-checked {
+  background-color: #404c59;
+  color: white;
+}
+
+/* Preview pane */
+
+#preview {
+  position: fixed;
+  height: 100vh;
+  margin-left: 66%;
+  width: 100%;
+}
+
+#submit-tasks {
+  display: flex;
+  flex-direction: column;
+  height: 80%;
+}
+
+#buttons {
+  display: flex;
+  justify-content: space-between;
+}
+
+#push {
+  background-color: #00e9b7;
+  margin-left: 5px;
+  width: 100%;
+}
+
+#selection {
+  height: 100%;
+  width: 100%;
+}
diff --git a/tools/tryselect/selectors/chooser/templates/chooser.html b/tools/tryselect/selectors/chooser/templates/chooser.html
new file mode 100644
index 0000000000..d89870ac77
--- /dev/null
+++ b/tools/tryselect/selectors/chooser/templates/chooser.html
@@ -0,0 +1,78 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this file,
+   - You can obtain one at http://mozilla.org/MPL/2.0/. -->
+
+{% extends 'layout.html' %}
+{% block content %}
+<div class="container-fluid">
+  <div class="row">
+    <div class="col-8">
+      <div class="form-group form-inline">
+        <span class="col-form-label col-md-2 pt-1">Build Type</span>
+        <div class="form-check form-check-inline">
+          <input id="both" class="filter form-check-input" type="radio" name="buildtype" value='{}' onchange="apply();" checked>
+          <label for="both" class="form-check-label">both</label>
+        </div>
+        {% for type in ["opt", "debug"] %}
+        <div class="form-check form-check-inline">
+          <input id="{{ type }}" class="filter form-check-input" type="radio" name="buildtype" value='{"build_type": "{{ type }}"}' onchange="apply();">
+          <label for={{ type }} class="form-check-label">{{ type }}</label>
+        </div>
+        {% endfor %}
+      </div>
+      <ul class="nav nav-tabs" id="tabbar" role="tablist">
+        {% for section in sections %}
+        <li class="nav-item">
+          {% if loop.first %}
+          <a class="nav-link active" id="{{ section.name }}-tab" data-toggle="tab" href="#{{section.name }}" role="tab" aria-controls="{{ section.name }}" aria-selected="true">{{ section.title }}</a>
+          {% else %}
+          <a class="nav-link" id="{{ section.name }}-tab" data-toggle="tab" href="#{{section.name }}" role="tab" aria-controls="{{ section.name }}" aria-selected="false">{{ section.title }}</a>
+          {% endif %}
+        </li>
+        {% endfor %}
+      </ul>
+      <div class="tab-content">
+        <button type="button" class="btn btn-secondary" value="true" onclick="selectAll(this);">Select All</button>
+        <button type="button" class="btn btn-secondary" onclick="selectAll(this);">Deselect All</button>
+        {% for section in sections %}
+        {% if loop.first %}
+        <div class="tab-pane show active" id="{{ section.name }}" role="tabpanel" aria-labelledby="{{ section.name }}-tab">
+        {% else %}
+        <div class="tab-pane" id="{{ section.name }}" role="tabpanel" aria-labelledby="{{ section.name }}-tab">
+        {% endif %}
+          {% for label, meta in section.labels|dictsort %}
+          <label class="multiselect filter-label" for={{ label }}>
+            <span>
+              {{ label }}
+              <input class="filter" type="checkbox" id={{ label }} name="{{ section.kind }}" value='{{ meta.attrs|tojson|safe }}' onchange="console.log('checkbox onchange triggered');apply();">
+              {% if meta.max_chunk > 1 %}
+              <input class="filter" type="text" pattern="^[0-9][0-9,-]*$" placeholder="1-{{ meta.max_chunk }}" name='{{ meta.attrs|tojson|safe }}' oninput="applyChunks();">
+              {% endif %}
+            </span>
+          </label>
+          {% endfor %}
+        </div>
+        {% endfor %}
+      </div>
+    </div>
+    <div class="col-4" id="preview">
+      <form id="submit-tasks" action="" method="POST">
+        <textarea id="selection" name="selected-tasks" wrap="off"></textarea>
+        <span id="selection-count">0 tasks selected</span><br>
+        <span id="buttons">
+          <input id="cancel" class="btn btn-default" type="submit" name="action" value="Cancel">
+          <input id="push" class="btn btn-default" type="submit" name="action" value="Push">
+        </span>
+      </form>
+    </div>
+  </div>
+</div>
+{% endblock %}
+
+{% block scripts %}
+<script>
+  const tasks = {{ tasks|tojson|safe }};
+</script>
+<script src="{{ url_for('static', filename='filter.js') }}"></script>
+<script src="{{ url_for('static', filename='select.js') }}"></script>
+{% endblock %}
diff --git a/tools/tryselect/selectors/chooser/templates/close.html b/tools/tryselect/selectors/chooser/templates/close.html
new file mode 100644
index 0000000000..622f9f38b2
--- /dev/null
+++ b/tools/tryselect/selectors/chooser/templates/close.html
@@ -0,0 +1,12 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this file,
+   - You can obtain one at http://mozilla.org/MPL/2.0/. -->
+
+{% extends 'layout.html' %}
+{% block content %}
+<div class="container-fluid">
+  <div class="alert alert-primary" role="alert">
+    You may now close this page.
+  </div>
+</div>
+{% endblock %}
diff --git a/tools/tryselect/selectors/chooser/templates/layout.html b/tools/tryselect/selectors/chooser/templates/layout.html
new file mode 100644
index 0000000000..4dfd27b46b
--- /dev/null
+++ b/tools/tryselect/selectors/chooser/templates/layout.html
@@ -0,0 +1,37 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this file,
+   - You can obtain one at http://mozilla.org/MPL/2.0/. -->
+
+<html>
+    <head>
+        <meta charset="utf-8">
+        <title>Try Chooser Enhanced</title>
+        <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css">
+        <link rel="stylesheet" href="{{ url_for('static', filename='style.css') }}">
+    </head>
+    <body>
+        <nav class="navbar navbar-default fixed-top navbar-dark bg-dark">
+          <div class="container-fluid">
+            <span class="navbar-brand mb-0 h1">Try Chooser Enhanced</span>
+            <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
+              <span class="navbar-toggler-icon"></span>
+            </button>
+            <div class="collapse navbar-collapse" id="navbarSupportedContent">
+              <ul class="navbar-nav mr-auto">
+                <li class="nav-item">
+                  <a class="nav-link" href="https://firefox-source-docs.mozilla.org/tools/try/index.html">Documentation</a>
+                </li>
+                <li class="nav-item">
+                  <a class="nav-link" href="https://treeherder.mozilla.org/#/jobs?repo=try">Treeherder</a>
+                </li>
+              </ul>
+            </div>
+          </div>
+        </nav>
+        {% block content %}{% endblock %}
+        <script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
+        <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.3/umd/popper.min.js" integrity="sha384-ZMP7rVo3mIykV+2+9J3UJ46jBk0WLaUAdn689aCwoqbBJiSnjAK/l8WvCWPIPm49" crossorigin="anonymous"></script>
+        <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js" integrity="sha384-ChfqqxuZUCnJSK3+MXmPNIyE6ZbWh2IMqE241rYiqJxyMiZ6OW/JmZQ5stwEULTy" crossorigin="anonymous"></script>
+        {% block scripts %}{% endblock %}
+    </body>
+</html>
diff --git a/tools/tryselect/selectors/compare.py b/tools/tryselect/selectors/compare.py
new file mode 100644
index 0000000000..a6e77ad61b
--- /dev/null
+++ b/tools/tryselect/selectors/compare.py
@@ -0,0 +1,56 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import os
+
+from mozbuild.base import MozbuildObject
+from mozversioncontrol import get_repository_object
+from tryselect.cli import BaseTryParser
+
+from .again import run as again_run
+from .fuzzy import run as fuzzy_run
+
+here = os.path.abspath(os.path.dirname(__file__))
+build = MozbuildObject.from_environment(cwd=here)
+
+
+class CompareParser(BaseTryParser):
+    name = "compare"
+    arguments = [
+        [
+            ["-cc", "--compare-commit"],
+            {
+                "default": None,
+                "help": "The commit that you want to compare your current revision with",
+            },
+        ],
+    ]
+    common_groups = ["task"]
+    task_configs = [
+        "rebuild",
+    ]
+
+    def get_revisions_to_run(vcs, compare_commit):
+        if compare_commit is None:
+            compare_commit = vcs.base_ref
+        if vcs.branch:
+            current_revision_ref = vcs.branch
+        else:
+            current_revision_ref = vcs.head_ref
+
+        return compare_commit, current_revision_ref
+
+
+def run(compare_commit=None, **kwargs):
+    vcs = get_repository_object(build.topsrcdir)
+    compare_commit, current_revision_ref = CompareParser.get_revisions_to_run(
+        vcs, compare_commit
+    )
+
+    try:
+        fuzzy_run(**kwargs)
+        vcs.update(compare_commit)
+        again_run()
+    finally:
+        vcs.update(current_revision_ref)
diff --git a/tools/tryselect/selectors/coverage.py b/tools/tryselect/selectors/coverage.py
new file mode 100644
index 0000000000..a871f35a11
--- /dev/null
+++ b/tools/tryselect/selectors/coverage.py
@@ -0,0 +1,447 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+import collections
+import datetime
+import hashlib
+import json
+import os
+import shutil
+import sqlite3
+import subprocess
+
+import requests
+import six
+from mach.util import get_state_dir
+from mozbuild.base import MozbuildObject
+from mozpack.files import FileFinder
+from moztest.resolve import TestResolver
+from mozversioncontrol import get_repository_object
+
+from ..cli import BaseTryParser
+from ..push import generate_try_task_config, push_to_try
+from ..tasks import filter_tasks_by_paths, generate_tasks, resolve_tests_by_suite
+
+here = os.path.abspath(os.path.dirname(__file__))
+build = None
+vcs = None
+CHUNK_MAPPING_FILE = None
+CHUNK_MAPPING_TAG_FILE = None
+
+
+def setup_globals():
+    # Avoid incurring expensive computation on import.
+    global build, vcs, CHUNK_MAPPING_TAG_FILE, CHUNK_MAPPING_FILE
+    build = MozbuildObject.from_environment(cwd=here)
+    vcs = get_repository_object(build.topsrcdir)
+
+    root_hash = hashlib.sha256(
+        six.ensure_binary(os.path.abspath(build.topsrcdir))
+    ).hexdigest()
+    cache_dir = os.path.join(get_state_dir(), "cache", root_hash, "chunk_mapping")
+    if not os.path.isdir(cache_dir):
+        os.makedirs(cache_dir)
+    CHUNK_MAPPING_FILE = os.path.join(cache_dir, "chunk_mapping.sqlite")
+    CHUNK_MAPPING_TAG_FILE = os.path.join(cache_dir, "chunk_mapping_tag.json")
+
+
+# Maps from platform names in the chunk_mapping sqlite database to respective
+# substrings in task names.
+PLATFORM_MAP = {
+    "linux": "test-linux64/opt",
+    "windows": "test-windows10-64/opt",
+}
+
+# List of platform/build type combinations that are included in pushes by |mach try coverage|.
+OPT_TASK_PATTERNS = [
+    "macosx64/opt",
+    "windows10-64/opt",
+    "windows7-32/opt",
+    "linux64/opt",
+]
+
+
+class CoverageParser(BaseTryParser):
+    name = "coverage"
+    arguments = []
+    common_groups = ["push", "task"]
+    task_configs = [
+        "artifact",
+        "env",
+        "rebuild",
+        "chemspill-prio",
+        "disable-pgo",
+        "worker-overrides",
+    ]
+
+
+def read_test_manifests():
+    """Uses TestResolver to read all test manifests in the tree.
+
+    Returns a (tests, support_files_map) tuple that describes the tests in the tree:
+    tests - a set of test file paths
+    support_files_map - a dict that maps from each support file to a list with
+                        test files that require them it
+    """
+    test_resolver = TestResolver.from_environment(cwd=here)
+    file_finder = FileFinder(build.topsrcdir)
+    support_files_map = collections.defaultdict(list)
+    tests = set()
+
+    for test in test_resolver.resolve_tests(build.topsrcdir):
+        tests.add(test["srcdir_relpath"])
+        if "support-files" not in test:
+            continue
+
+        for support_file_pattern in test["support-files"].split():
+            # Get the pattern relative to topsrcdir.
+            if support_file_pattern.startswith("!/"):
+                support_file_pattern = support_file_pattern[2:]
+            elif support_file_pattern.startswith("/"):
+                support_file_pattern = support_file_pattern[1:]
+            else:
+                support_file_pattern = os.path.normpath(
+                    os.path.join(test["dir_relpath"], support_file_pattern)
+                )
+
+            # If it doesn't have a glob, then it's a single file.
+            if "*" not in support_file_pattern:
+                # Simple case: single support file, just add it here.
+                support_files_map[support_file_pattern].append(test["srcdir_relpath"])
+                continue
+
+            for support_file, _ in file_finder.find(support_file_pattern):
+                support_files_map[support_file].append(test["srcdir_relpath"])
+
+    return tests, support_files_map
+
+
+# TODO cache the output of this function
+all_tests, all_support_files = read_test_manifests()
+
+
+def download_coverage_mapping(base_revision):
+    try:
+        with open(CHUNK_MAPPING_TAG_FILE) as f:
+            tags = json.load(f)
+            if tags["target_revision"] == base_revision:
+                return
+            else:
+                print("Base revision changed.")
+    except (OSError, ValueError):
+        print("Chunk mapping file not found.")
+
+    CHUNK_MAPPING_URL_TEMPLATE = "https://firefox-ci-tc.services.mozilla.com/api/index/v1/task/project.relman.code-coverage.production.cron.{}/artifacts/public/chunk_mapping.tar.xz"  # noqa
+    JSON_PUSHES_URL_TEMPLATE = "https://hg.mozilla.org/mozilla-central/json-pushes?version=2&tipsonly=1&startdate={}"  # noqa
+
+    # Get pushes from at most one month ago.
+    PUSH_HISTORY_DAYS = 30
+    delta = datetime.timedelta(days=PUSH_HISTORY_DAYS)
+    start_time = (datetime.datetime.now() - delta).strftime("%Y-%m-%d")
+    pushes_url = JSON_PUSHES_URL_TEMPLATE.format(start_time)
+    pushes_data = requests.get(pushes_url + "&tochange={}".format(base_revision)).json()
+    if "error" in pushes_data:
+        if "unknown revision" in pushes_data["error"]:
+            print(
+                "unknown revision {}, trying with latest mozilla-central".format(
+                    base_revision
+                )
+            )
+            pushes_data = requests.get(pushes_url).json()
+
+        if "error" in pushes_data:
+            raise Exception(pushes_data["error"])
+
+    pushes = pushes_data["pushes"]
+
+    print("Looking for coverage data. This might take a minute or two.")
+    print("Base revision:", base_revision)
+    for push_id in sorted(pushes.keys())[::-1]:
+        rev = pushes[push_id]["changesets"][0]
+        url = CHUNK_MAPPING_URL_TEMPLATE.format(rev)
+        print("push id: {},\trevision: {}".format(push_id, rev))
+
+        r = requests.head(url)
+        if not r.ok:
+            continue
+
+        print("Chunk mapping found, downloading...")
+        r = requests.get(url, stream=True)
+
+        CHUNK_MAPPING_ARCHIVE = os.path.join(build.topsrcdir, "chunk_mapping.tar.xz")
+        with open(CHUNK_MAPPING_ARCHIVE, "wb") as f:
+            r.raw.decode_content = True
+            shutil.copyfileobj(r.raw, f)
+
+        subprocess.check_call(
+            [
+                "tar",
+                "-xJf",
+                CHUNK_MAPPING_ARCHIVE,
+                "-C",
+                os.path.dirname(CHUNK_MAPPING_FILE),
+            ]
+        )
+        os.remove(CHUNK_MAPPING_ARCHIVE)
+        assert os.path.isfile(CHUNK_MAPPING_FILE)
+        with open(CHUNK_MAPPING_TAG_FILE, "w") as f:
+            json.dump(
+                {
+                    "target_revision": base_revision,
+                    "chunk_mapping_revision": rev,
+                    "download_date": start_time,
+                },
+                f,
+            )
+        return
+    raise Exception("Could not find suitable coverage data.")
+
+
+def is_a_test(cursor, path):
+    """Checks the all_tests global and the chunk mapping database to see if a
+    given file is a test file.
+    """
+    if path in all_tests:
+        return True
+
+    cursor.execute("SELECT COUNT(*) from chunk_to_test WHERE path=?", (path,))
+    if cursor.fetchone()[0]:
+        return True
+
+    cursor.execute("SELECT COUNT(*) from file_to_test WHERE test=?", (path,))
+    if cursor.fetchone()[0]:
+        return True
+
+    return False
+
+
+def tests_covering_file(cursor, path):
+    """Returns a set of tests that cover a given source file."""
+    cursor.execute("SELECT test FROM file_to_test WHERE source=?", (path,))
+    return {e[0] for e in cursor.fetchall()}
+
+
+def tests_in_chunk(cursor, platform, chunk):
+    """Returns a set of tests that are contained in a given chunk."""
+    cursor.execute(
+        "SELECT path FROM chunk_to_test WHERE platform=? AND chunk=?", (platform, chunk)
+    )
+    # Because of bug 1480103, some entries in this table contain both a file name and a test name,
+    # separated by a space. With the split, only the file name is kept.
+    return {e[0].split(" ")[0] for e in cursor.fetchall()}
+
+
+def chunks_covering_file(cursor, path):
+    """Returns a set of (platform, chunk) tuples with the chunks that cover a given source file."""
+    cursor.execute("SELECT platform, chunk FROM file_to_chunk WHERE path=?", (path,))
+    return set(cursor.fetchall())
+
+
+def tests_supported_by_file(path):
+    """Returns a set of tests that are using the given file as a support-file."""
+    return set(all_support_files[path])
+
+
+def find_tests(changed_files):
+    """Finds both individual tests and test chunks that should be run to test code changes.
+    Argument: a list of file paths relative to the source checkout.
+
+    Returns: a (test_files, test_chunks) tuple with two sets.
+    test_files - contains tests that should be run to verify changes to changed_files.
+    test_chunks - contains (platform, chunk) tuples with chunks that should be
+                  run. These chunnks do not support running a subset of the tests (like
+                  cppunit or gtest), so the whole chunk must be run.
+    """
+    test_files = set()
+    test_chunks = set()
+    files_no_coverage = set()
+
+    with sqlite3.connect(CHUNK_MAPPING_FILE) as conn:
+        c = conn.cursor()
+        for path in changed_files:
+            # If path is a test, add it to the list and continue.
+            if is_a_test(c, path):
+                test_files.add(path)
+                continue
+
+            # Look at the chunk mapping and add all tests that cover this file.
+            tests = tests_covering_file(c, path)
+            chunks = chunks_covering_file(c, path)
+            # If we found tests covering this, then it's not a support-file, so
+            # save these and continue.
+            if tests or chunks:
+                test_files |= tests
+                test_chunks |= chunks
+                continue
+
+            # Check if the path is a support-file for any test, by querying test manifests.
+            tests = tests_supported_by_file(path)
+            if tests:
+                test_files |= tests
+                continue
+
+            # There is no coverage information for this file.
+            files_no_coverage.add(path)
+
+        files_covered = set(changed_files) - files_no_coverage
+        test_files = {s.replace("\\", "/") for s in test_files}
+
+        _print_found_tests(files_covered, files_no_coverage, test_files, test_chunks)
+
+        remaining_test_chunks = set()
+        # For all test_chunks, try to find the tests contained by them in the
+        # chunk_to_test mapping.
+        for platform, chunk in test_chunks:
+            tests = tests_in_chunk(c, platform, chunk)
+            if tests:
+                for test in tests:
+                    test_files.add(test.replace("\\", "/"))
+            else:
+                remaining_test_chunks.add((platform, chunk))
+
+    return test_files, remaining_test_chunks
+
+
+def _print_found_tests(files_covered, files_no_coverage, test_files, test_chunks):
+    """Print a summary of what will be run to the user's terminal."""
+    files_covered = sorted(files_covered)
+    files_no_coverage = sorted(files_no_coverage)
+    test_files = sorted(test_files)
+    test_chunks = sorted(test_chunks)
+
+    if files_covered:
+        print(
+            "Found {} modified source files with test coverage:".format(
+                len(files_covered)
+            )
+        )
+        for covered in files_covered:
+            print("\t", covered)
+
+    if files_no_coverage:
+        print(
+            "Found {} modified source files with no coverage:".format(
+                len(files_no_coverage)
+            )
+        )
+        for f in files_no_coverage:
+            print("\t", f)
+
+    if not files_covered:
+        print("No modified source files are covered by tests.")
+    elif not files_no_coverage:
+        print("All modified source files are covered by tests.")
+
+    if test_files:
+        print("Running {} individual test files.".format(len(test_files)))
+    else:
+        print("Could not find any individual tests to run.")
+
+    if test_chunks:
+        print("Running {} test chunks.".format(len(test_chunks)))
+        for platform, chunk in test_chunks:
+            print("\t", platform, chunk)
+    else:
+        print("Could not find any test chunks to run.")
+
+
+def filter_tasks_by_chunks(tasks, chunks):
+    """Find all tasks that will run the given chunks."""
+    selected_tasks = set()
+    for platform, chunk in chunks:
+        platform = PLATFORM_MAP[platform]
+
+        selected_task = None
+        for task in tasks:
+            if not task.startswith(platform):
+                continue
+
+            if not any(
+                task[len(platform) + 1 :].endswith(c) for c in [chunk, chunk + "-e10s"]
+            ):
+                continue
+
+            assert (
+                selected_task is None
+            ), "Only one task should be selected for a given platform-chunk couple ({} - {}), {} and {} were selected".format(  # noqa
+                platform, chunk, selected_task, task
+            )
+            selected_task = task
+
+        if selected_task is None:
+            print("Warning: no task found for chunk", platform, chunk)
+        else:
+            selected_tasks.add(selected_task)
+
+    return list(selected_tasks)
+
+
+def is_opt_task(task):
+    """True if the task runs on a supported platform and build type combination.
+    This is used to remove -ccov/asan/pgo tasks, along with all /debug tasks.
+    """
+    return any(platform in task for platform in OPT_TASK_PATTERNS)
+
+
+def run(
+    try_config={},
+    full=False,
+    parameters=None,
+    stage_changes=False,
+    dry_run=False,
+    message="{msg}",
+    closed_tree=False,
+):
+    setup_globals()
+    download_coverage_mapping(vcs.base_ref)
+
+    changed_sources = vcs.get_outgoing_files()
+    test_files, test_chunks = find_tests(changed_sources)
+    if not test_files and not test_chunks:
+        print("ERROR Could not find any tests or chunks to run.")
+        return 1
+
+    tg = generate_tasks(parameters, full)
+    all_tasks = tg.tasks.keys()
+
+    tasks_by_chunks = filter_tasks_by_chunks(all_tasks, test_chunks)
+    tasks_by_path = filter_tasks_by_paths(all_tasks, test_files)
+    tasks = filter(is_opt_task, set(tasks_by_path) | set(tasks_by_chunks))
+    tasks = list(tasks)
+
+    if not tasks:
+        print("ERROR Did not find any matching tasks after filtering.")
+        return 1
+    test_count_message = (
+        "{test_count} test file{test_plural} that "
+        + "cover{test_singular} these changes "
+        + "({task_count} task{task_plural} to be scheduled)"
+    ).format(
+        test_count=len(test_files),
+        test_plural="" if len(test_files) == 1 else "s",
+        test_singular="s" if len(test_files) == 1 else "",
+        task_count=len(tasks),
+        task_plural="" if len(tasks) == 1 else "s",
+    )
+    print("Found " + test_count_message)
+
+    # Set the test paths to be run by setting MOZHARNESS_TEST_PATHS.
+    path_env = {
+        "MOZHARNESS_TEST_PATHS": six.ensure_text(
+            json.dumps(resolve_tests_by_suite(test_files))
+        )
+    }
+    try_config.setdefault("env", {}).update(path_env)
+
+    # Build commit message.
+    msg = "try coverage - " + test_count_message
+    return push_to_try(
+        "coverage",
+        message.format(msg=msg),
+        try_task_config=generate_try_task_config("coverage", tasks, try_config),
+        stage_changes=stage_changes,
+        dry_run=dry_run,
+        closed_tree=closed_tree,
+    )
diff --git a/tools/tryselect/selectors/empty.py b/tools/tryselect/selectors/empty.py
new file mode 100644
index 0000000000..2465999c90
--- /dev/null
+++ b/tools/tryselect/selectors/empty.py
@@ -0,0 +1,24 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+from ..cli import BaseTryParser
+from ..push import generate_try_task_config, push_to_try
+
+
+class EmptyParser(BaseTryParser):
+    name = "empty"
+    common_groups = ["push"]
+
+
+def run(message="{msg}", stage_changes=False, dry_run=False, closed_tree=False):
+    msg = 'No try selector specified, use "Add New Jobs" to select tasks.'
+    return push_to_try(
+        "empty",
+        message.format(msg=msg),
+        try_task_config=generate_try_task_config("empty", []),
+        stage_changes=stage_changes,
+        dry_run=dry_run,
+        closed_tree=closed_tree,
+    )
diff --git a/tools/tryselect/selectors/fuzzy.py b/tools/tryselect/selectors/fuzzy.py
new file mode 100644
index 0000000000..03fc0531d4
--- /dev/null
+++ b/tools/tryselect/selectors/fuzzy.py
@@ -0,0 +1,255 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+import os
+import sys
+from pathlib import PurePath
+
+from gecko_taskgraph.target_tasks import filter_by_uncommon_try_tasks
+from mach.util import get_state_dir
+
+from ..cli import BaseTryParser
+from ..push import check_working_directory, generate_try_task_config, push_to_try
+from ..tasks import filter_tasks_by_paths, generate_tasks
+from ..util.fzf import (
+    FZF_NOT_FOUND,
+    PREVIEW_SCRIPT,
+    format_header,
+    fzf_bootstrap,
+    fzf_shortcuts,
+    run_fzf,
+)
+from ..util.manage_estimates import (
+    download_task_history_data,
+    make_trimmed_taskgraph_cache,
+)
+
+
+class FuzzyParser(BaseTryParser):
+    name = "fuzzy"
+    arguments = [
+        [
+            ["-q", "--query"],
+            {
+                "metavar": "STR",
+                "action": "append",
+                "default": [],
+                "help": "Use the given query instead of entering the selection "
+                "interface. Equivalent to typing <query><ctrl-a><enter> "
+                "from the interface. Specifying multiple times schedules "
+                "the union of computed tasks.",
+            },
+        ],
+        [
+            ["-i", "--interactive"],
+            {
+                "action": "store_true",
+                "default": False,
+                "help": "Force running fzf interactively even when using presets or "
+                "queries with -q/--query.",
+            },
+        ],
+        [
+            ["-x", "--and"],
+            {
+                "dest": "intersection",
+                "action": "store_true",
+                "default": False,
+                "help": "When specifying queries on the command line with -q/--query, "
+                "use the intersection of tasks rather than the union. This is "
+                "especially useful for post filtering presets.",
+            },
+        ],
+        [
+            ["-e", "--exact"],
+            {
+                "action": "store_true",
+                "default": False,
+                "help": "Enable exact match mode. Terms will use an exact match "
+                "by default, and terms prefixed with ' will become fuzzy.",
+            },
+        ],
+        [
+            ["-u", "--update"],
+            {
+                "action": "store_true",
+                "default": False,
+                "help": "Update fzf before running.",
+            },
+        ],
+        [
+            ["-s", "--show-estimates"],
+            {
+                "action": "store_true",
+                "default": False,
+                "help": "Show task duration estimates.",
+            },
+        ],
+        [
+            ["--disable-target-task-filter"],
+            {
+                "action": "store_true",
+                "default": False,
+                "help": "Some tasks run on mozilla-central but are filtered out "
+                "of the default list due to resource constraints. This flag "
+                "disables this filtering.",
+            },
+        ],
+    ]
+    common_groups = ["push", "task", "preset"]
+    task_configs = [
+        "artifact",
+        "browsertime",
+        "chemspill-prio",
+        "disable-pgo",
+        "env",
+        "gecko-profile",
+        "path",
+        "pernosco",
+        "rebuild",
+        "routes",
+        "worker-overrides",
+    ]
+
+
+def run(
+    update=False,
+    query=None,
+    intersect_query=None,
+    try_config=None,
+    full=False,
+    parameters=None,
+    save_query=False,
+    stage_changes=False,
+    dry_run=False,
+    message="{msg}",
+    test_paths=None,
+    exact=False,
+    closed_tree=False,
+    show_estimates=False,
+    disable_target_task_filter=False,
+):
+    fzf = fzf_bootstrap(update)
+
+    if not fzf:
+        print(FZF_NOT_FOUND)
+        return 1
+
+    push = not stage_changes and not dry_run
+    check_working_directory(push)
+    tg = generate_tasks(
+        parameters, full=full, disable_target_task_filter=disable_target_task_filter
+    )
+    all_tasks = sorted(tg.tasks.keys())
+
+    # graph_Cache created by generate_tasks, recreate the path to that file.
+    cache_dir = os.path.join(
+        get_state_dir(specific_to_topsrcdir=True), "cache", "taskgraph"
+    )
+    if full:
+        graph_cache = os.path.join(cache_dir, "full_task_graph")
+        dep_cache = os.path.join(cache_dir, "full_task_dependencies")
+        target_set = os.path.join(cache_dir, "full_task_set")
+    else:
+        graph_cache = os.path.join(cache_dir, "target_task_graph")
+        dep_cache = os.path.join(cache_dir, "target_task_dependencies")
+        target_set = os.path.join(cache_dir, "target_task_set")
+
+    if show_estimates:
+        download_task_history_data(cache_dir=cache_dir)
+        make_trimmed_taskgraph_cache(graph_cache, dep_cache, target_file=target_set)
+
+    if not full and not disable_target_task_filter:
+        # Put all_tasks into a list because it's used multiple times, and "filter()"
+        # returns a consumable iterator.
+        all_tasks = list(filter(filter_by_uncommon_try_tasks, all_tasks))
+
+    if test_paths:
+        all_tasks = filter_tasks_by_paths(all_tasks, test_paths)
+        if not all_tasks:
+            return 1
+
+    key_shortcuts = [k + ":" + v for k, v in fzf_shortcuts.items()]
+    base_cmd = [
+        fzf,
+        "-m",
+        "--bind",
+        ",".join(key_shortcuts),
+        "--header",
+        format_header(),
+        "--preview-window=right:30%",
+        "--print-query",
+    ]
+
+    if show_estimates:
+        base_cmd.extend(
+            [
+                "--preview",
+                '{} {} -g {} -s -c {} -t "{{+f}}"'.format(
+                    str(PurePath(sys.executable)), PREVIEW_SCRIPT, dep_cache, cache_dir
+                ),
+            ]
+        )
+    else:
+        base_cmd.extend(
+            [
+                "--preview",
+                '{} {} -t "{{+f}}"'.format(
+                    str(PurePath(sys.executable)), PREVIEW_SCRIPT
+                ),
+            ]
+        )
+
+    if exact:
+        base_cmd.append("--exact")
+
+    selected = set()
+    queries = []
+
+    def get_tasks(query_arg=None, candidate_tasks=all_tasks):
+        cmd = base_cmd[:]
+        if query_arg and query_arg != "INTERACTIVE":
+            cmd.extend(["-f", query_arg])
+
+        query_str, tasks = run_fzf(cmd, sorted(candidate_tasks))
+        queries.append(query_str)
+        return set(tasks)
+
+    for q in query or []:
+        selected |= get_tasks(q)
+
+    for q in intersect_query or []:
+        if not selected:
+            tasks = get_tasks(q)
+            selected |= tasks
+        else:
+            tasks = get_tasks(q, selected)
+            selected &= tasks
+
+    if not queries:
+        selected = get_tasks()
+
+    if not selected:
+        print("no tasks selected")
+        return
+
+    if save_query:
+        return queries
+
+    # build commit message
+    msg = "Fuzzy"
+    args = ["query={}".format(q) for q in queries]
+    if test_paths:
+        args.append("paths={}".format(":".join(test_paths)))
+    if args:
+        msg = "{} {}".format(msg, "&".join(args))
+    return push_to_try(
+        "fuzzy",
+        message.format(msg=msg),
+        try_task_config=generate_try_task_config("fuzzy", selected, try_config),
+        stage_changes=stage_changes,
+        dry_run=dry_run,
+        closed_tree=closed_tree,
+    )
diff --git a/tools/tryselect/selectors/perf.py b/tools/tryselect/selectors/perf.py
new file mode 100644
index 0000000000..418ceaef8f
--- /dev/null
+++ b/tools/tryselect/selectors/perf.py
@@ -0,0 +1,1306 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import copy
+import enum
+import itertools
+import os
+import re
+import sys
+from contextlib import redirect_stdout
+
+from mozbuild.base import MozbuildObject
+from mozversioncontrol import get_repository_object
+
+from ..push import generate_try_task_config, push_to_try
+from ..util.fzf import (
+    FZF_NOT_FOUND,
+    build_base_cmd,
+    fzf_bootstrap,
+    run_fzf,
+    setup_tasks_for_fzf,
+)
+from .compare import CompareParser
+
+here = os.path.abspath(os.path.dirname(__file__))
+build = MozbuildObject.from_environment(cwd=here)
+
+PERFHERDER_BASE_URL = (
+    "https://treeherder.mozilla.org/perfherder/"
+    "compare?originalProject=try&originalRevision=%s&newProject=try&newRevision=%s"
+)
+
+# Prevent users from running more than 300 tests at once. It's possible, but
+# it's more likely that a query is broken and is selecting far too much.
+MAX_PERF_TASKS = 300
+REVISION_MATCHER = re.compile(r"remote:.*/try/rev/([\w]*)[ \t]*$")
+
+# Name of the base category with no variants applied to it
+BASE_CATEGORY_NAME = "base"
+
+
+class InvalidCategoryException(Exception):
+    """Thrown when a category is found to be invalid.
+
+    See the `PerfParser.run_category_checks()` method for more info.
+    """
+
+    pass
+
+
+class LogProcessor:
+    def __init__(self):
+        self.buf = ""
+        self.stdout = sys.__stdout__
+        self._revision = None
+
+    @property
+    def revision(self):
+        return self._revision
+
+    def write(self, buf):
+        while buf:
+            try:
+                newline_index = buf.index("\n")
+            except ValueError:
+                # No newline, wait for next call
+                self.buf += buf
+                break
+
+            # Get data up to next newline and combine with previously buffered data
+            data = self.buf + buf[: newline_index + 1]
+            buf = buf[newline_index + 1 :]
+
+            # Reset buffer then output line
+            self.buf = ""
+            if data.strip() == "":
+                continue
+            self.stdout.write(data.strip("\n") + "\n")
+
+            # Check if a temporary commit wa created
+            match = REVISION_MATCHER.match(data)
+            if match:
+                # Last line found is the revision we want
+                self._revision = match.group(1)
+
+
+class ClassificationEnum(enum.Enum):
+    """This class provides the ability to use Enums as array indices."""
+
+    @property
+    def value(self):
+        return self._value_["value"]
+
+    def __index__(self):
+        return self._value_["index"]
+
+    def __int__(self):
+        return self._value_["index"]
+
+
+class Platforms(ClassificationEnum):
+    ANDROID_A51 = {"value": "android-a51", "index": 0}
+    ANDROID = {"value": "android", "index": 1}
+    WINDOWS = {"value": "windows", "index": 2}
+    LINUX = {"value": "linux", "index": 3}
+    MACOSX = {"value": "macosx", "index": 4}
+    DESKTOP = {"value": "desktop", "index": 5}
+
+
+class Apps(ClassificationEnum):
+    FIREFOX = {"value": "firefox", "index": 0}
+    CHROME = {"value": "chrome", "index": 1}
+    CHROMIUM = {"value": "chromium", "index": 2}
+    GECKOVIEW = {"value": "geckoview", "index": 3}
+    FENIX = {"value": "fenix", "index": 4}
+    CHROME_M = {"value": "chrome-m", "index": 5}
+    SAFARI = {"value": "safari", "index": 6}
+
+
+class Suites(ClassificationEnum):
+    RAPTOR = {"value": "raptor", "index": 0}
+    TALOS = {"value": "talos", "index": 1}
+    AWSY = {"value": "awsy", "index": 2}
+
+
+class Variants(ClassificationEnum):
+    NO_FISSION = {"value": "no-fission", "index": 0}
+    BYTECODE_CACHED = {"value": "bytecode-cached", "index": 1}
+    LIVE_SITES = {"value": "live-sites", "index": 2}
+    PROFILING = {"value": "profiling", "index": 3}
+    SWR = {"value": "swr", "index": 4}
+
+
+"""
+The following methods and constants are used for restricting
+certain platforms and applications such as chrome, safari, and
+android tests. These all require a flag such as --android to
+enable (see build_category_matrix for more info).
+"""
+
+
+def check_for_android(android=False, **kwargs):
+    return android
+
+
+def check_for_chrome(chrome=False, **kwargs):
+    return chrome
+
+
+def check_for_safari(safari=False, **kwargs):
+    return safari
+
+
+def check_for_live_sites(live_sites=False, **kwargs):
+    return live_sites
+
+
+def check_for_profile(profile=False, **kwargs):
+    return profile
+
+
+class PerfParser(CompareParser):
+    name = "perf"
+    common_groups = ["push", "task"]
+    task_configs = [
+        "artifact",
+        "browsertime",
+        "disable-pgo",
+        "env",
+        "gecko-profile",
+        "path",
+        "rebuild",
+    ]
+
+    platforms = {
+        Platforms.ANDROID_A51.value: {
+            "query": "'android 'a51 'shippable 'aarch64",
+            "restriction": check_for_android,
+            "platform": Platforms.ANDROID.value,
+        },
+        Platforms.ANDROID.value: {
+            # The android, and android-a51 queries are expected to be the same,
+            # we don't want to run the tests on other mobile platforms.
+            "query": "'android 'a51 'shippable 'aarch64",
+            "restriction": check_for_android,
+            "platform": Platforms.ANDROID.value,
+        },
+        Platforms.WINDOWS.value: {
+            "query": "!-32 'windows 'shippable",
+            "platform": Platforms.DESKTOP.value,
+        },
+        Platforms.LINUX.value: {
+            "query": "!clang 'linux 'shippable",
+            "platform": Platforms.DESKTOP.value,
+        },
+        Platforms.MACOSX.value: {
+            "query": "'osx 'shippable",
+            "platform": Platforms.DESKTOP.value,
+        },
+        Platforms.DESKTOP.value: {
+            "query": "!android 'shippable !-32 !clang",
+            "platform": Platforms.DESKTOP.value,
+        },
+    }
+
+    apps = {
+        Apps.FIREFOX.value: {
+            "query": "!chrom !geckoview !fenix !safari",
+            "platforms": [Platforms.DESKTOP.value],
+        },
+        Apps.CHROME.value: {
+            "query": "'chrome",
+            "negation": "!chrom",
+            "restriction": check_for_chrome,
+            "platforms": [Platforms.DESKTOP.value],
+        },
+        Apps.CHROMIUM.value: {
+            "query": "'chromium",
+            "negation": "!chrom",
+            "restriction": check_for_chrome,
+            "platforms": [Platforms.DESKTOP.value],
+        },
+        Apps.GECKOVIEW.value: {
+            "query": "'geckoview",
+            "platforms": [Platforms.ANDROID.value],
+        },
+        Apps.FENIX.value: {
+            "query": "'fenix",
+            "platforms": [Platforms.ANDROID.value],
+        },
+        Apps.CHROME_M.value: {
+            "query": "'chrome-m",
+            "negation": "!chrom",
+            "restriction": check_for_chrome,
+            "platforms": [Platforms.ANDROID.value],
+        },
+        Apps.SAFARI.value: {
+            "query": "'safari",
+            "negation": "!safari",
+            "restriction": check_for_safari,
+            "platforms": [Platforms.MACOSX.value],
+        },
+    }
+
+    variants = {
+        Variants.NO_FISSION.value: {
+            "query": "'nofis",
+            "negation": "!nofis",
+            "platforms": [Platforms.ANDROID.value],
+            "apps": [Apps.FENIX.value, Apps.GECKOVIEW.value],
+        },
+        Variants.BYTECODE_CACHED.value: {
+            "query": "'bytecode",
+            "negation": "!bytecode",
+            "platforms": [Platforms.DESKTOP.value],
+            "apps": [Apps.FIREFOX.value],
+        },
+        Variants.LIVE_SITES.value: {
+            "query": "'live",
+            "negation": "!live",
+            "restriction": check_for_live_sites,
+            "platforms": [Platforms.DESKTOP.value, Platforms.ANDROID.value],
+            "apps": list(apps.keys()),
+        },
+        Variants.PROFILING.value: {
+            "query": "'profil",
+            "negation": "!profil",
+            "restriction": check_for_profile,
+            "platforms": [Platforms.DESKTOP.value, Platforms.ANDROID.value],
+            "apps": [Apps.FIREFOX.value, Apps.GECKOVIEW.value, Apps.FENIX.value],
+        },
+        Variants.SWR.value: {
+            "query": "'swr",
+            "negation": "!swr",
+            "platforms": [Platforms.DESKTOP.value],
+            "apps": [Apps.FIREFOX.value],
+        },
+    }
+
+    suites = {
+        Suites.RAPTOR.value: {
+            "apps": list(apps.keys()),
+            "platforms": list(platforms.keys()),
+            "variants": [
+                Variants.NO_FISSION.value,
+                Variants.LIVE_SITES.value,
+                Variants.PROFILING.value,
+                Variants.BYTECODE_CACHED.value,
+            ],
+        },
+        Suites.TALOS.value: {
+            "apps": [Apps.FIREFOX.value],
+            "platforms": [Platforms.DESKTOP.value],
+            "variants": [
+                Variants.PROFILING.value,
+                Variants.SWR.value,
+            ],
+        },
+        Suites.AWSY.value: {
+            "apps": [Apps.FIREFOX.value],
+            "platforms": [Platforms.DESKTOP.value],
+            "variants": [],
+        },
+    }
+
+    """
+    Here you can find the base categories that are defined for the perf
+    selector. The following fields are available:
+        * query: Set the queries to use for each suite you need.
+        * suites: The suites that are needed for this category.
+        * tasks: A hard-coded list of tasks to select.
+        * platforms: The platforms that it can run on.
+        * app-restrictions: A list of apps that the category can run.
+        * variant-restrictions: A list of variants available for each suite.
+
+    Note that setting the App/Variant-Restriction fields should be used to
+    restrict the available apps and variants, not expand them.
+    """
+    categories = {
+        "Pageload": {
+            "query": {
+                Suites.RAPTOR.value: ["'browsertime 'tp6"],
+            },
+            "suites": [Suites.RAPTOR.value],
+            "tasks": [],
+        },
+        "Pageload (essential)": {
+            "query": {
+                Suites.RAPTOR.value: ["'browsertime 'tp6 'essential"],
+            },
+            "variant-restrictions": {Suites.RAPTOR.value: [Variants.NO_FISSION.value]},
+            "suites": [Suites.RAPTOR.value],
+            "app-restrictions": {
+                Suites.RAPTOR.value: [
+                    Apps.FIREFOX.value,
+                    Apps.CHROME.value,
+                    Apps.CHROMIUM.value,
+                    Apps.FENIX.value,
+                    Apps.GECKOVIEW.value,
+                ],
+            },
+            "tasks": [],
+        },
+        "Responsiveness": {
+            "query": {
+                Suites.RAPTOR.value: ["'browsertime 'responsive"],
+            },
+            "suites": [Suites.RAPTOR.value],
+            "variant-restrictions": {Suites.RAPTOR.value: []},
+            "app-restrictions": {
+                Suites.RAPTOR.value: [
+                    Apps.FIREFOX.value,
+                    Apps.CHROME.value,
+                    Apps.CHROMIUM.value,
+                    Apps.FENIX.value,
+                    Apps.GECKOVIEW.value,
+                ],
+            },
+            "tasks": [],
+        },
+        "Benchmarks": {
+            "query": {
+                Suites.RAPTOR.value: ["'browsertime 'benchmark"],
+            },
+            "suites": [Suites.RAPTOR.value],
+            "variant-restrictions": {Suites.RAPTOR.value: []},
+            "tasks": [],
+        },
+        "DAMP (Devtools)": {
+            "query": {
+                Suites.TALOS.value: ["'talos 'damp"],
+            },
+            "suites": [Suites.TALOS.value],
+            "tasks": [],
+        },
+        "Talos PerfTests": {
+            "query": {
+                Suites.TALOS.value: ["'talos"],
+            },
+            "suites": [Suites.TALOS.value],
+            "tasks": [],
+        },
+        "Resource Usage": {
+            "query": {
+                Suites.TALOS.value: ["'talos 'xperf | 'tp5"],
+                Suites.RAPTOR.value: ["'power 'osx"],
+                Suites.AWSY.value: ["'awsy"],
+            },
+            "suites": [Suites.TALOS.value, Suites.RAPTOR.value, Suites.AWSY.value],
+            "platform-restrictions": [Platforms.DESKTOP.value],
+            "variant-restrictions": {
+                Suites.RAPTOR.value: [],
+                Suites.TALOS.value: [],
+            },
+            "app-restrictions": {
+                Suites.RAPTOR.value: [Apps.FIREFOX.value],
+                Suites.TALOS.value: [Apps.FIREFOX.value],
+            },
+            "tasks": [],
+        },
+        "Graphics, & Media Playback": {
+            "query": {
+                # XXX This might not be an exhaustive list for talos atm
+                Suites.TALOS.value: ["'talos 'svgr | 'bcv | 'webgl"],
+                Suites.RAPTOR.value: ["'browsertime 'youtube-playback"],
+            },
+            "suites": [Suites.TALOS.value, Suites.RAPTOR.value],
+            "variant-restrictions": {Suites.RAPTOR.value: [Variants.NO_FISSION.value]},
+            "app-restrictions": {
+                Suites.RAPTOR.value: [
+                    Apps.FIREFOX.value,
+                    Apps.CHROME.value,
+                    Apps.CHROMIUM.value,
+                    Apps.FENIX.value,
+                    Apps.GECKOVIEW.value,
+                ],
+            },
+            "tasks": [],
+        },
+    }
+
+    arguments = [
+        [
+            ["--show-all"],
+            {
+                "action": "store_true",
+                "default": False,
+                "help": "Show all available tasks.",
+            },
+        ],
+        [
+            ["--android"],
+            {
+                "action": "store_true",
+                "default": False,
+                "help": "Show android test categories (disabled by default).",
+            },
+        ],
+        [
+            ["--chrome"],
+            {
+                "action": "store_true",
+                "default": False,
+                "help": "Show tests available for Chrome-based browsers "
+                "(disabled by default).",
+            },
+        ],
+        [
+            ["--safari"],
+            {
+                "action": "store_true",
+                "default": False,
+                "help": "Show tests available for Safari (disabled by default).",
+            },
+        ],
+        [
+            ["--live-sites"],
+            {
+                "action": "store_true",
+                "default": False,
+                "help": "Run tasks with live sites (if possible). "
+                "You can also use the `live-sites` variant.",
+            },
+        ],
+        [
+            ["--profile"],
+            {
+                "action": "store_true",
+                "default": False,
+                "help": "Run tasks with profiling (if possible). "
+                "You can also use the `profiling` variant.",
+            },
+        ],
+        [
+            ["--single-run"],
+            {
+                "action": "store_true",
+                "default": False,
+                "help": "Run tasks without a comparison",
+            },
+        ],
+        [
+            ["--variants"],
+            {
+                "nargs": "*",
+                "type": str,
+                "default": [BASE_CATEGORY_NAME],
+                "dest": "requested_variants",
+                "choices": list(variants.keys()),
+                "help": "Select variants to display in the selector from: "
+                + ", ".join(list(variants.keys())),
+                "metavar": "",
+            },
+        ],
+        [
+            ["--platforms"],
+            {
+                "nargs": "*",
+                "type": str,
+                "default": [],
+                "dest": "requested_platforms",
+                "choices": list(platforms.keys()),
+                "help": "Select specific platforms to target. Android only "
+                "available with --android. Available platforms: "
+                + ", ".join(list(platforms.keys())),
+                "metavar": "",
+            },
+        ],
+        [
+            ["--apps"],
+            {
+                "nargs": "*",
+                "type": str,
+                "default": [],
+                "dest": "requested_apps",
+                "choices": list(apps.keys()),
+                "help": "Select specific applications to target from: "
+                + ", ".join(list(apps.keys())),
+                "metavar": "",
+            },
+        ],
+    ]
+
+    def get_tasks(base_cmd, queries, query_arg=None, candidate_tasks=None):
+        cmd = base_cmd[:]
+        if query_arg:
+            cmd.extend(["-f", query_arg])
+
+        query_str, tasks = run_fzf(cmd, sorted(candidate_tasks))
+        queries.append(query_str)
+        return set(tasks)
+
+    def get_perf_tasks(base_cmd, all_tg_tasks, perf_categories):
+        # Convert the categories to tasks
+        selected_tasks = set()
+        queries = []
+
+        selected_categories = PerfParser.get_tasks(
+            base_cmd, queries, None, perf_categories
+        )
+
+        for category, category_info in perf_categories.items():
+            if category not in selected_categories:
+                continue
+            print("Gathering tasks for %s category" % category)
+
+            category_tasks = set()
+            for suite in PerfParser.suites:
+                # Either perform a query to get the tasks (recommended), or
+                # use a hardcoded task list
+                suite_queries = category_info["queries"].get(suite)
+
+                category_suite_tasks = set()
+                if suite_queries:
+                    print(
+                        "Executing %s queries: %s" % (suite, ", ".join(suite_queries))
+                    )
+
+                    for perf_query in suite_queries:
+                        if not category_suite_tasks:
+                            # Get all tasks selected with the first query
+                            category_suite_tasks |= PerfParser.get_tasks(
+                                base_cmd, queries, perf_query, all_tg_tasks
+                            )
+                        else:
+                            # Keep only those tasks that matched in all previous queries
+                            category_suite_tasks &= PerfParser.get_tasks(
+                                base_cmd, queries, perf_query, category_suite_tasks
+                            )
+
+                        if len(category_suite_tasks) == 0:
+                            print("Failed to find any tasks for query: %s" % perf_query)
+                            break
+
+                    if category_suite_tasks:
+                        category_tasks |= category_suite_tasks
+
+            if category_info["tasks"]:
+                category_tasks = set(category_info["tasks"]) & all_tg_tasks
+                if category_tasks != set(category_info["tasks"]):
+                    print(
+                        "Some expected tasks could not be found: %s"
+                        % ", ".join(category_info["tasks"] - category_tasks)
+                    )
+
+            if not category_tasks:
+                print("Could not find any tasks for category %s" % category)
+            else:
+                # Add the new tasks to the currently selected ones
+                selected_tasks |= category_tasks
+
+        if len(selected_tasks) > MAX_PERF_TASKS:
+            print(
+                "That's a lot of tests selected (%s)!\n"
+                "These tests won't be triggered. If this was unexpected, "
+                "please file a bug in Testing :: Performance." % MAX_PERF_TASKS
+            )
+            return [], [], []
+
+        return selected_tasks, selected_categories, queries
+
+    def _check_app(app, target):
+        """Checks if the app exists in the target."""
+        if app.value in target:
+            return True
+        return False
+
+    def _check_platform(platform, target):
+        """Checks if the platform, or it's type exists in the target."""
+        if (
+            platform.value in target
+            or PerfParser.platforms[platform.value]["platform"] in target
+        ):
+            return True
+        return False
+
+    def _build_initial_decision_matrix():
+        # Build first stage of matrix APPS X PLATFORMS
+        initial_decision_matrix = []
+        for platform in Platforms:
+            platform_row = []
+            for app in Apps:
+                if PerfParser._check_platform(
+                    platform, PerfParser.apps[app.value]["platforms"]
+                ):
+                    # This app can run on this platform
+                    platform_row.append(True)
+                else:
+                    platform_row.append(False)
+            initial_decision_matrix.append(platform_row)
+        return initial_decision_matrix
+
+    def _build_intermediate_decision_matrix():
+        # Second stage of matrix building applies the 2D matrix found above
+        # to each suite
+        initial_decision_matrix = PerfParser._build_initial_decision_matrix()
+
+        intermediate_decision_matrix = []
+        for suite in Suites:
+            suite_matrix = copy.deepcopy(initial_decision_matrix)
+            suite_info = PerfParser.suites[suite.value]
+
+            # Restric the platforms for this suite now
+            for platform in Platforms:
+                for app in Apps:
+                    runnable = False
+                    if PerfParser._check_app(
+                        app, suite_info["apps"]
+                    ) and PerfParser._check_platform(platform, suite_info["platforms"]):
+                        runnable = True
+                    suite_matrix[platform][app] = (
+                        runnable and suite_matrix[platform][app]
+                    )
+
+            intermediate_decision_matrix.append(suite_matrix)
+        return intermediate_decision_matrix
+
+    def _build_variants_matrix():
+        # Third stage is expanding the intermediate matrix
+        # across all the variants (non-expanded). Start with the
+        # intermediate matrix in the list since it provides our
+        # base case with no variants
+        intermediate_decision_matrix = PerfParser._build_intermediate_decision_matrix()
+
+        variants_matrix = []
+        for variant in Variants:
+            variant_matrix = copy.deepcopy(intermediate_decision_matrix)
+
+            for suite in Suites:
+                if variant.value in PerfParser.suites[suite.value]["variants"]:
+                    # Allow the variant through and set it's platforms and apps
+                    # based on how it sets it -> only restrict, don't make allowances
+                    # here
+                    for platform in Platforms:
+                        for app in Apps:
+                            if not (
+                                PerfParser._check_platform(
+                                    platform,
+                                    PerfParser.variants[variant.value]["platforms"],
+                                )
+                                and PerfParser._check_app(
+                                    app, PerfParser.variants[variant.value]["apps"]
+                                )
+                            ):
+                                variant_matrix[suite][platform][app] = False
+                else:
+                    # This variant matrix needs to be completely False
+                    variant_matrix[suite] = [
+                        [False] * len(platform_row)
+                        for platform_row in variant_matrix[suite]
+                    ]
+
+            variants_matrix.append(variant_matrix)
+
+        return variants_matrix, intermediate_decision_matrix
+
+    def _build_decision_matrix():
+        """Build the decision matrix.
+
+        This method builds the decision matrix that is used
+        to determine what categories will be shown to the user.
+        This matrix has the following form (as lists):
+            - Variants
+                - Suites
+                    - Platforms
+                        - Apps
+
+        Each element in the 4D Matrix is either True or False and tells us
+        whether the particular combination is "runnable" according to
+        the given specifications. This does not mean that the combination
+        exists, just that it's fully configured in this selector.
+
+        The ("base",) variant combination found in the matrix has
+        no variants applied to it. At this stage, it's a catch-all for those
+        categories. The query it uses is reduced further in later stages.
+        """
+        # Get the variants matrix (see methods above) and the intermediate decision
+        # matrix to act as the base category
+        (
+            variants_matrix,
+            intermediate_decision_matrix,
+        ) = PerfParser._build_variants_matrix()
+
+        # Get all possible combinations of the variants
+        expanded_variants = [
+            variant_combination
+            for set_size in range(len(Variants) + 1)
+            for variant_combination in itertools.combinations(list(Variants), set_size)
+        ]
+
+        # Final stage combines the intermediate matrix with the
+        # expanded variants and leaves a "base" category which
+        # doesn't have any variant specifications (it catches them all)
+        decision_matrix = {(BASE_CATEGORY_NAME,): intermediate_decision_matrix}
+        for variant_combination in expanded_variants:
+            expanded_variant_matrix = []
+
+            # Perform an AND operation on the combination of variants
+            # to determine where this particular combination can run
+            for suite in Suites:
+                suite_matrix = []
+                suite_variants = PerfParser.suites[suite.value]["variants"]
+
+                # Disable the variant combination if none of them
+                # are found in the suite
+                disable_variant = not any(
+                    [variant.value in suite_variants for variant in variant_combination]
+                )
+
+                for platform in Platforms:
+                    if disable_variant:
+                        platform_row = [False for _ in Apps]
+                    else:
+                        platform_row = [
+                            all(
+                                variants_matrix[variant][suite][platform][app]
+                                for variant in variant_combination
+                                if variant.value in suite_variants
+                            )
+                            for app in Apps
+                        ]
+                    suite_matrix.append(platform_row)
+
+                expanded_variant_matrix.append(suite_matrix)
+            decision_matrix[variant_combination] = expanded_variant_matrix
+
+        return decision_matrix
+
+    def _skip_with_restrictions(value, restrictions, requested=[]):
+        """Determines if we should skip an app, platform, or variant.
+
+        We add base here since it's the base category variant that
+        would always be displayed and it won't affect the app, or
+        platform selections.
+        """
+        if restrictions is not None and value not in restrictions + [
+            BASE_CATEGORY_NAME
+        ]:
+            return True
+        if requested and value not in requested + [BASE_CATEGORY_NAME]:
+            return True
+        return False
+
+    def build_category_matrix(
+        requested_variants=[BASE_CATEGORY_NAME],
+        requested_platforms=[],
+        requested_apps=[],
+        **kwargs,
+    ):
+        """Build a decision matrix for all the categories.
+
+        It will have the form:
+            - Category
+                - Variants
+                    - ...
+        """
+        # Build the base decision matrix
+        decision_matrix = PerfParser._build_decision_matrix()
+
+        # Here, the variants are further restricted by the category settings
+        # using the `_skip_with_restrictions` method. This part also handles
+        # explicitly requested platforms, apps, and variants.
+        category_decision_matrix = {}
+        for category, category_info in PerfParser.categories.items():
+            category_matrix = copy.deepcopy(decision_matrix)
+
+            for variant_combination, variant_matrix in decision_matrix.items():
+                variant_runnable = True
+                if BASE_CATEGORY_NAME not in variant_combination:
+                    # Make sure that all portions of the variant combination
+                    # target at least one of the suites in the category
+                    tmp_variant_combination = set(
+                        [v.value for v in variant_combination]
+                    )
+                    for suite in Suites:
+                        if suite.value not in category_info["suites"]:
+                            continue
+                        tmp_variant_combination = tmp_variant_combination - set(
+                            [
+                                variant.value
+                                for variant in variant_combination
+                                if variant.value
+                                in PerfParser.suites[suite.value]["variants"]
+                            ]
+                        )
+                    if tmp_variant_combination:
+                        # If it's not empty, then some variants
+                        # are non-existent
+                        variant_runnable = False
+
+                for suite, platform, app in itertools.product(Suites, Platforms, Apps):
+                    runnable = variant_runnable
+
+                    # Disable this combination if there are any variant
+                    # restrictions for this suite, or if the user didn't request it
+                    # (and did request some variants). The same is done below with
+                    # the apps, and platforms.
+                    if any(
+                        PerfParser._skip_with_restrictions(
+                            variant.value if not isinstance(variant, str) else variant,
+                            category_info.get("variant-restrictions", {}).get(
+                                suite.value, None
+                            ),
+                            requested_variants,
+                        )
+                        for variant in variant_combination
+                    ):
+                        runnable = False
+
+                    if PerfParser._skip_with_restrictions(
+                        platform.value,
+                        category_info.get("platform-restrictions", None),
+                        requested_platforms,
+                    ):
+                        runnable = False
+
+                    # If the platform is restricted, check if the appropriate
+                    # flags were provided (or appropriate conditions hit). We do
+                    # the same thing for apps below.
+                    if (
+                        PerfParser.platforms[platform.value].get("restriction", None)
+                        is not None
+                    ):
+                        runnable = runnable and PerfParser.platforms[platform.value][
+                            "restriction"
+                        ](**kwargs)
+
+                    if PerfParser._skip_with_restrictions(
+                        app.value,
+                        category_info.get("app-restrictions", {}).get(
+                            suite.value, None
+                        ),
+                        requested_apps,
+                    ):
+                        runnable = False
+                    if PerfParser.apps[app.value].get("restriction", None) is not None:
+                        runnable = runnable and PerfParser.apps[app.value][
+                            "restriction"
+                        ](**kwargs)
+
+                    category_matrix[variant_combination][suite][platform][app] = (
+                        runnable and variant_matrix[suite][platform][app]
+                    )
+
+            category_decision_matrix[category] = category_matrix
+
+        return category_decision_matrix
+
+    def _enable_restriction(restriction, **kwargs):
+        """Used to simplify checking a restriction."""
+        return restriction is not None and restriction(**kwargs)
+
+    def _category_suites(category_info):
+        """Returns all the suite enum entries in this category."""
+        return [suite for suite in Suites if suite.value in category_info["suites"]]
+
+    def _add_variant_queries(
+        category_info, variant_matrix, variant_combination, platform, queries, app=None
+    ):
+        """Used to add the variant queries to various categories."""
+        for variant in variant_combination:
+            for suite in PerfParser._category_suites(category_info):
+                if (app is not None and variant_matrix[suite][platform][app]) or (
+                    app is None and any(variant_matrix[suite][platform])
+                ):
+                    queries[suite.value].append(
+                        PerfParser.variants[variant.value]["query"]
+                    )
+
+    def _build_categories(category, category_info, category_matrix):
+        """Builds the categories to display."""
+        categories = {}
+
+        for variant_combination, variant_matrix in category_matrix.items():
+            base_category = BASE_CATEGORY_NAME in variant_combination
+
+            for platform in Platforms:
+                if not any(
+                    any(variant_matrix[suite][platform])
+                    for suite in PerfParser._category_suites(category_info)
+                ):
+                    # There are no apps available on this platform in either
+                    # of the requested suites
+                    continue
+
+                # This code has the effect of restricting all suites to
+                # a platform. This means categories with mixed suites will
+                # be available even if some suites will no longer run
+                # given this platform constraint. The reasoning for this is that
+                # it's unexpected to receive desktop tests when you explcitly
+                # request android.
+                platform_queries = {
+                    suite: (
+                        category_info["query"][suite]
+                        + [PerfParser.platforms[platform.value]["query"]]
+                    )
+                    for suite in category_info["suites"]
+                }
+
+                platform_category_name = f"{category} {platform.value}"
+                platform_category_info = {
+                    "queries": platform_queries,
+                    "tasks": category_info["tasks"],
+                    "platform": platform,
+                    "app": None,
+                    "suites": category_info["suites"],
+                    "base-category": base_category,
+                    "base-category-name": category,
+                }
+                for app in Apps:
+                    if not any(
+                        variant_matrix[suite][platform][app]
+                        for suite in PerfParser._category_suites(category_info)
+                    ):
+                        # This app is not available on the given platform
+                        # for any of the suites
+                        continue
+
+                    # Add the queries for the app for any suites that need it and
+                    # the variant queries if needed
+                    app_queries = copy.deepcopy(platform_queries)
+                    for suite in Suites:
+                        if suite.value not in app_queries:
+                            continue
+                        app_queries[suite.value].append(
+                            PerfParser.apps[app.value]["query"]
+                        )
+                    if not base_category:
+                        PerfParser._add_variant_queries(
+                            category_info,
+                            variant_matrix,
+                            variant_combination,
+                            platform,
+                            app_queries,
+                            app=app,
+                        )
+
+                    app_category_name = f"{platform_category_name} {app.value}"
+                    if not base_category:
+                        app_category_name = (
+                            f"{app_category_name} "
+                            f"{'+'.join([v.value for v in variant_combination])}"
+                        )
+                    categories[app_category_name] = {
+                        "queries": app_queries,
+                        "tasks": category_info["tasks"],
+                        "platform": platform,
+                        "app": app,
+                        "suites": category_info["suites"],
+                        "base-category": base_category,
+                    }
+
+                if not base_category:
+                    platform_category_name = (
+                        f"{platform_category_name} "
+                        f"{'+'.join([v.value for v in variant_combination])}"
+                    )
+                    PerfParser._add_variant_queries(
+                        category_info,
+                        variant_matrix,
+                        variant_combination,
+                        platform,
+                        platform_queries,
+                    )
+                categories[platform_category_name] = platform_category_info
+
+        return categories
+
+    def _handle_variant_negations(category, category_info, **kwargs):
+        """Handle variant negations.
+
+        The reason why we're negating variants here instead of where we add
+        them to the queries is because we need to iterate over all of the variants
+        but when we add them, we only look at the variants in the combination. It's
+        possible to combine these, but that increases the complexity of the code
+        by quite a bit so it's best to do it separately.
+        """
+        for variant in Variants:
+            if category_info["base-category"] and variant.value in kwargs.get(
+                "requested_variants", [BASE_CATEGORY_NAME]
+            ):
+                # When some particular variant(s) are requested, and we are at a
+                # base category, don't negate it. Otherwise, if the variant
+                # wasn't requested negate it
+                continue
+            if variant.value in category:
+                # If this variant is in the category name, skip negations
+                continue
+            if not PerfParser._check_platform(
+                category_info["platform"],
+                PerfParser.variants[variant.value]["platforms"],
+            ):
+                # Make sure the variant applies to the platform
+                continue
+
+            for suite in category_info["suites"]:
+                if variant.value not in PerfParser.suites[suite]["variants"]:
+                    continue
+                category_info["queries"][suite].append(
+                    PerfParser.variants[variant.value]["negation"]
+                )
+
+    def _handle_app_negations(category, category_info, **kwargs):
+        """Handle app negations.
+
+        This is where the global chrome/safari negations get added. We use kwargs
+        along with the app restriction method to make this decision.
+        """
+        for app in Apps:
+            if PerfParser.apps[app.value].get("negation", None) is None:
+                continue
+            elif any(
+                PerfParser.apps[app.value]["negation"]
+                in category_info["queries"][suite]
+                for suite in category_info["suites"]
+            ):
+                # Already added the negations
+                continue
+            if category_info.get("app", None) is not None:
+                # We only need to handle this for categories that
+                # don't specify an app
+                continue
+            if PerfParser._enable_restriction(
+                PerfParser.apps[app.value].get("restriction", None), **kwargs
+            ):
+                continue
+
+            for suite in category_info["suites"]:
+                if app.value not in PerfParser.suites[suite]["apps"]:
+                    continue
+                category_info["queries"][suite].append(
+                    PerfParser.apps[app.value]["negation"]
+                )
+
+    def _handle_negations(category, category_info, **kwargs):
+        """This method handles negations.
+
+        This method should only include things that should be globally applied
+        to all the queries. The apps are included as chrome is negated if
+        --chrome isn't provided, and the variants are negated here too.
+        """
+        PerfParser._handle_variant_negations(category, category_info, **kwargs)
+        PerfParser._handle_app_negations(category, category_info, **kwargs)
+
+    def get_categories(**kwargs):
+        """Get the categories to be displayed.
+
+        The categories are built using the decision matrices from `build_category_matrix`.
+        The methods above provide more detail on how this is done. Here, we use
+        this matrix to determine if we should show a category to a user.
+
+        We also apply the negations for restricted apps/platforms and variants
+        at the end before displaying the categories.
+        """
+        categories = {}
+
+        # Setup the restrictions, and ease-of-use variants requested (if any)
+        for variant in Variants:
+            if PerfParser._enable_restriction(
+                PerfParser.variants[variant.value].get("restriction", None), **kwargs
+            ):
+                kwargs.setdefault("requested_variants", []).append(variant.value)
+
+        category_decision_matrix = PerfParser.build_category_matrix(**kwargs)
+
+        # Now produce the categories by finding all the entries that are True
+        for category, category_matrix in category_decision_matrix.items():
+            categories.update(
+                PerfParser._build_categories(
+                    category, PerfParser.categories[category], category_matrix
+                )
+            )
+
+        # Handle the restricted app queries, and variant negations
+        for category, category_info in categories.items():
+            PerfParser._handle_negations(category, category_info, **kwargs)
+
+        return categories
+
+    def perf_push_to_try(
+        selected_tasks, selected_categories, queries, try_config, dry_run, single_run
+    ):
+        """Perf-specific push to try method.
+
+        This makes use of logic from the CompareParser to do something
+        very similar except with log redirection. We get the comparison
+        revisions, then use the repository object to update between revisions
+        and the LogProcessor for parsing out the revisions that are used
+        to build the Perfherder links.
+        """
+        vcs = get_repository_object(build.topsrcdir)
+        compare_commit, current_revision_ref = PerfParser.get_revisions_to_run(
+            vcs, None
+        )
+
+        # Build commit message
+        msg = "Perf selections={} (queries={})".format(
+            ",".join(selected_categories),
+            "&".join([q for q in queries if q is not None and len(q) > 0]),
+        )
+
+        updated = False
+        new_revision_treeherder = ""
+        base_revision_treeherder = ""
+        try:
+            # redirect_stdout allows us to feed each line into
+            # a processor that we can use to catch the revision
+            # while providing real-time output
+            log_processor = LogProcessor()
+            with redirect_stdout(log_processor):
+                push_to_try(
+                    "perf",
+                    "{msg}".format(msg=msg),
+                    # XXX Figure out if changing `fuzzy` to `perf` will break something
+                    try_task_config=generate_try_task_config(
+                        "fuzzy", selected_tasks, try_config
+                    ),
+                    stage_changes=False,
+                    dry_run=dry_run,
+                    closed_tree=False,
+                    allow_log_capture=True,
+                )
+
+            new_revision_treeherder = log_processor.revision
+
+            if not (dry_run or single_run):
+                vcs.update(compare_commit)
+                updated = True
+
+                with redirect_stdout(log_processor):
+                    # XXX Figure out if we can use the `again` selector in some way
+                    # Right now we would need to modify it to be able to do this.
+                    # XXX Fix up the again selector for the perf selector (if it makes sense to)
+                    push_to_try(
+                        "perf-again",
+                        "{msg}".format(msg=msg),
+                        try_task_config=generate_try_task_config(
+                            "fuzzy", selected_tasks, try_config
+                        ),
+                        stage_changes=False,
+                        dry_run=dry_run,
+                        closed_tree=False,
+                        allow_log_capture=True,
+                    )
+
+                base_revision_treeherder = log_processor.revision
+        finally:
+            if updated:
+                vcs.update(current_revision_ref)
+
+        return base_revision_treeherder, new_revision_treeherder
+
+    def run(
+        update=False,
+        show_all=False,
+        parameters=None,
+        try_config=None,
+        dry_run=False,
+        single_run=False,
+        **kwargs,
+    ):
+        # Setup fzf
+        fzf = fzf_bootstrap(update)
+
+        if not fzf:
+            print(FZF_NOT_FOUND)
+            return 1
+
+        all_tasks, dep_cache, cache_dir = setup_tasks_for_fzf(
+            not dry_run,
+            parameters,
+            full=True,
+            disable_target_task_filter=False,
+        )
+        base_cmd = build_base_cmd(fzf, dep_cache, cache_dir, show_estimates=False)
+
+        # Perform the selection, then push to try and return the revisions
+        queries = []
+        selected_categories = []
+        if not show_all:
+            # Expand the categories first
+            categories = PerfParser.get_categories(**kwargs)
+            selected_tasks, selected_categories, queries = PerfParser.get_perf_tasks(
+                base_cmd, all_tasks, categories
+            )
+        else:
+            selected_tasks = PerfParser.get_tasks(base_cmd, queries, None, all_tasks)
+
+        if len(selected_tasks) == 0:
+            print("No tasks selected")
+            return None
+
+        return PerfParser.perf_push_to_try(
+            selected_tasks,
+            selected_categories,
+            queries,
+            try_config,
+            dry_run,
+            single_run,
+        )
+
+    def run_category_checks():
+        # XXX: Add a jsonschema check for the category definition
+        # Make sure the queries don't specify variants in them
+        variant_queries = {
+            suite: [
+                PerfParser.variants[variant]["query"]
+                for variant in suite_info.get(
+                    "variants", list(PerfParser.variants.keys())
+                )
+            ]
+            + [
+                PerfParser.variants[variant]["negation"]
+                for variant in suite_info.get(
+                    "variants", list(PerfParser.variants.keys())
+                )
+            ]
+            for suite, suite_info in PerfParser.suites.items()
+        }
+
+        for category, category_info in PerfParser.categories.items():
+            for suite, query in category_info["query"].items():
+                if len(variant_queries[suite]) == 0:
+                    # This suite has no variants
+                    continue
+                if any(any(v in q for q in query) for v in variant_queries[suite]):
+                    raise InvalidCategoryException(
+                        f"The '{category}' category suite query for '{suite}' "
+                        f"uses a variant in it's query '{query}'."
+                        "If you don't want a particular variant use the "
+                        "`variant-restrictions` field in the category."
+                    )
+
+        return True
+
+
+def run(**kwargs):
+    # Make sure the categories are following
+    # the rules we've setup
+    PerfParser.run_category_checks()
+
+    revisions = PerfParser.run(
+        profile=kwargs.get("try_config", {}).get("gecko-profile", False),
+        **kwargs,
+    )
+
+    if revisions is None:
+        return
+
+    # Provide link to perfherder for comparisons now
+    if not kwargs.get("single_run", False):
+        perfcompare_url = PERFHERDER_BASE_URL % revisions
+        print(
+            "\n!!!NOTE!!!\n You'll be able to find a performance comparison here "
+            "once the tests are complete (ensure you select the right "
+            "framework): %s\n" % perfcompare_url
+        )
+    print(
+        "If you need any help, you can find us in the #perf-help Matrix channel:\n"
+        "https://matrix.to/#/#perf-help:mozilla.org\n"
+    )
+    print(
+        "For more information on the performance tests, see our PerfDocs here:\n"
+        "https://firefox-source-docs.mozilla.org/testing/perfdocs/"
+    )
diff --git a/tools/tryselect/selectors/preview.py b/tools/tryselect/selectors/preview.py
new file mode 100644
index 0000000000..1d232af9e0
--- /dev/null
+++ b/tools/tryselect/selectors/preview.py
@@ -0,0 +1,102 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+"""This script is intended to be called through fzf as a preview formatter."""
+
+
+import argparse
+import os
+import sys
+
+here = os.path.abspath(os.path.dirname(__file__))
+sys.path.insert(0, os.path.join(os.path.dirname(here), "util"))
+from estimates import duration_summary
+
+
+def process_args():
+    """Process preview arguments."""
+    argparser = argparse.ArgumentParser()
+    argparser.add_argument(
+        "-s",
+        "--show-estimates",
+        action="store_true",
+        help="Show task duration estimates (default: False)",
+    )
+    argparser.add_argument(
+        "-g",
+        "--graph-cache",
+        type=str,
+        default=None,
+        help="Filename of task graph dependencies",
+    )
+    argparser.add_argument(
+        "-c",
+        "--cache_dir",
+        type=str,
+        default=None,
+        help="Path to cache directory containing task durations",
+    )
+    argparser.add_argument(
+        "-t",
+        "--tasklist",
+        type=str,
+        default=None,
+        help="Path to temporary file containing the selected tasks",
+    )
+    return argparser.parse_args()
+
+
+def plain_display(taskfile):
+    """Original preview window display."""
+    with open(taskfile) as f:
+        tasklist = [line.strip() for line in f]
+    print("\n".join(sorted(tasklist)))
+
+
+def duration_display(graph_cache_file, taskfile, cache_dir):
+    """Preview window display with task durations + metadata."""
+    with open(taskfile) as f:
+        tasklist = [line.strip() for line in f]
+
+    durations = duration_summary(graph_cache_file, tasklist, cache_dir)
+    output = ""
+    max_columns = int(os.environ["FZF_PREVIEW_COLUMNS"])
+
+    output += "\nSelected tasks take {}\n".format(durations["selected_duration"])
+    output += "+{} dependencies, total {}\n".format(
+        durations["dependency_count"],
+        durations["selected_duration"] + durations["dependency_duration"],
+    )
+
+    if durations.get("percentile"):
+        output += "This is in the top {}% of requests\n".format(
+            100 - durations["percentile"]
+        )
+
+    output += "Estimated finish in {} at {}".format(
+        durations["wall_duration_seconds"], durations["eta_datetime"].strftime("%H:%M")
+    )
+
+    duration_width = 5  # show five numbers at most.
+    output += "{:>{width}}\n".format("Duration", width=max_columns)
+    for task in tasklist:
+        duration = durations["task_durations"].get(task, 0.0)
+        output += "{:{align}{width}} {:{nalign}{nwidth}}s\n".format(
+            task,
+            duration,
+            align="<",
+            width=max_columns - (duration_width + 2),  # 2: space and 's'
+            nalign=">",
+            nwidth=duration_width,
+        )
+
+    print(output)
+
+
+if __name__ == "__main__":
+    args = process_args()
+    if args.show_estimates and os.path.isdir(args.cache_dir):
+        duration_display(args.graph_cache, args.tasklist, args.cache_dir)
+    else:
+        plain_display(args.tasklist)
diff --git a/tools/tryselect/selectors/release.py b/tools/tryselect/selectors/release.py
new file mode 100644
index 0000000000..a828b3d038
--- /dev/null
+++ b/tools/tryselect/selectors/release.py
@@ -0,0 +1,159 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+import os
+
+import attr
+import yaml
+from mozilla_version.gecko import FirefoxVersion
+
+from ..cli import BaseTryParser
+from ..push import push_to_try, vcs
+
+TARGET_TASKS = {
+    "staging": "staging_release_builds",
+    "release-sim": "release_simulation",
+}
+
+
+def read_file(path):
+    with open(path) as fh:
+        return fh.read()
+
+
+class ReleaseParser(BaseTryParser):
+    name = "release"
+    arguments = [
+        [
+            ["-v", "--version"],
+            {
+                "metavar": "STR",
+                "required": True,
+                "action": "store",
+                "type": FirefoxVersion.parse,
+                "help": "The version number to use for the staging release.",
+            },
+        ],
+        [
+            ["--migration"],
+            {
+                "metavar": "STR",
+                "action": "append",
+                "dest": "migrations",
+                "choices": [
+                    "central-to-beta",
+                    "beta-to-release",
+                    "early-to-late-beta",
+                    "release-to-esr",
+                ],
+                "help": "Migration to run for the release (can be specified multiple times).",
+            },
+        ],
+        [
+            ["--no-limit-locales"],
+            {
+                "action": "store_false",
+                "dest": "limit_locales",
+                "help": "Don't build a limited number of locales in the staging release.",
+            },
+        ],
+        [
+            ["--tasks"],
+            {
+                "choices": TARGET_TASKS.keys(),
+                "default": "staging",
+                "help": "Which tasks to run on-push.",
+            },
+        ],
+    ]
+    common_groups = ["push"]
+    task_configs = ["disable-pgo", "worker-overrides"]
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.set_defaults(migrations=[])
+
+
+def run(
+    version,
+    migrations,
+    limit_locales,
+    tasks,
+    try_config=None,
+    stage_changes=False,
+    dry_run=False,
+    message="{msg}",
+    closed_tree=False,
+):
+    app_version = attr.evolve(version, beta_number=None, is_esr=False)
+
+    files_to_change = {
+        "browser/config/version.txt": "{}\n".format(app_version),
+        "browser/config/version_display.txt": "{}\n".format(version),
+        "config/milestone.txt": "{}\n".format(app_version),
+    }
+    with open("browser/config/version.txt") as f:
+        current_version = FirefoxVersion.parse(f.read())
+    format_options = {
+        "current_major_version": current_version.major_number,
+        "next_major_version": version.major_number,
+        "current_weave_version": current_version.major_number + 2,
+        "next_weave_version": version.major_number + 2,
+    }
+
+    if "beta-to-release" in migrations and "early-to-late-beta" not in migrations:
+        migrations.append("early-to-late-beta")
+
+    release_type = version.version_type.name.lower()
+    if release_type not in ("beta", "release", "esr"):
+        raise Exception(
+            "Can't do staging release for version: {} type: {}".format(
+                version, version.version_type
+            )
+        )
+    elif release_type == "esr":
+        release_type += str(version.major_number)
+    task_config = {
+        "version": 2,
+        "parameters": {
+            "target_tasks_method": TARGET_TASKS[tasks],
+            "optimize_target_tasks": True,
+            "release_type": release_type,
+        },
+    }
+    if try_config:
+        task_config["parameters"]["try_task_config"] = try_config
+
+    with open(os.path.join(vcs.path, "taskcluster/ci/config.yml")) as f:
+        migration_configs = yaml.safe_load(f)
+    for migration in migrations:
+        migration_config = migration_configs["merge-automation"]["behaviors"][migration]
+        for (path, from_, to) in migration_config["replacements"]:
+            if path in files_to_change:
+                contents = files_to_change[path]
+            else:
+                contents = read_file(path)
+            from_ = from_.format(**format_options)
+            to = to.format(**format_options)
+            files_to_change[path] = contents.replace(from_, to)
+
+    if limit_locales:
+        files_to_change["browser/locales/l10n-changesets.json"] = read_file(
+            os.path.join(vcs.path, "browser/locales/l10n-onchange-changesets.json")
+        )
+        files_to_change["browser/locales/shipped-locales"] = "en-US\n" + read_file(
+            os.path.join(vcs.path, "browser/locales/onchange-locales")
+        )
+
+    msg = "staging release: {}".format(version)
+    return push_to_try(
+        "release",
+        message.format(msg=msg),
+        stage_changes=stage_changes,
+        dry_run=dry_run,
+        closed_tree=closed_tree,
+        try_task_config=task_config,
+        files_to_change=files_to_change,
+    )
diff --git a/tools/tryselect/selectors/scriptworker.py b/tools/tryselect/selectors/scriptworker.py
new file mode 100644
index 0000000000..984ad26a88
--- /dev/null
+++ b/tools/tryselect/selectors/scriptworker.py
@@ -0,0 +1,177 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+import sys
+
+import requests
+from gecko_taskgraph.util.taskgraph import find_existing_tasks
+from taskgraph.parameters import Parameters
+from taskgraph.util.taskcluster import find_task_id, get_artifact, get_session
+
+from ..cli import BaseTryParser
+from ..push import push_to_try
+
+TASK_TYPES = {
+    "linux-signing": [
+        "build-signing-linux-shippable/opt",
+        "build-signing-linux64-shippable/opt",
+        "build-signing-win64-shippable/opt",
+        "build-signing-win32-shippable/opt",
+        "repackage-signing-win64-shippable/opt",
+        "repackage-signing-win32-shippable/opt",
+        "repackage-signing-msi-win32-shippable/opt",
+        "repackage-signing-msi-win64-shippable/opt",
+        "mar-signing-linux64-shippable/opt",
+    ],
+    "linux-signing-partial": ["partials-signing-linux64-shippable/opt"],
+    "mac-signing": ["build-signing-macosx64-shippable/opt"],
+    "beetmover-candidates": ["beetmover-repackage-linux64-shippable/opt"],
+    "bouncer-submit": ["release-bouncer-sub-firefox"],
+    "balrog-submit": [
+        "release-balrog-submit-toplevel-firefox",
+        "balrog-linux64-shippable/opt",
+    ],
+    "tree": ["release-early-tagging-firefox", "release-version-bump-firefox"],
+}
+
+RELEASE_TO_BRANCH = {
+    "beta": "releases/mozilla-beta",
+    "release": "releases/mozilla-release",
+}
+
+
+class ScriptworkerParser(BaseTryParser):
+    name = "scriptworker"
+    arguments = [
+        [
+            ["task_type"],
+            {
+                "choices": ["list"] + list(TASK_TYPES.keys()),
+                "metavar": "TASK-TYPE",
+                "help": "Scriptworker task types to run. (Use `list` to show possibilities)",
+            },
+        ],
+        [
+            ["--release-type"],
+            {
+                "choices": ["nightly"] + list(RELEASE_TO_BRANCH.keys()),
+                "default": "beta",
+                "help": "Release type to run",
+            },
+        ],
+    ]
+
+    common_groups = ["push"]
+    task_configs = ["worker-overrides", "routes"]
+
+
+def get_releases(branch):
+    response = requests.get(
+        "https://shipitapi-public.services.mozilla.com/releases",
+        params={"product": "firefox", "branch": branch, "status": "shipped"},
+        headers={"Accept": "application/json"},
+    )
+    response.raise_for_status()
+    return response.json()
+
+
+def get_release_graph(release):
+    for phase in release["phases"]:
+        if phase["name"] in ("ship_firefox",):
+            return phase["actionTaskId"]
+    raise Exception("No ship phase.")
+
+
+def get_nightly_graph():
+    return find_task_id(
+        "gecko.v2.mozilla-central.latest.taskgraph.decision-nightly-desktop"
+    )
+
+
+def print_available_task_types():
+    print("Available task types:")
+    for task_type, tasks in TASK_TYPES.items():
+        print(" " * 4 + "{}:".format(task_type))
+        for task in tasks:
+            print(" " * 8 + "- {}".format(task))
+
+
+def get_hg_file(parameters, path):
+    session = get_session()
+    response = session.get(parameters.file_url(path))
+    response.raise_for_status()
+    return response.content
+
+
+def run(
+    task_type,
+    release_type,
+    try_config=None,
+    stage_changes=False,
+    dry_run=False,
+    message="{msg}",
+    closed_tree=False,
+):
+    if task_type == "list":
+        print_available_task_types()
+        sys.exit(0)
+
+    if release_type == "nightly":
+        previous_graph = get_nightly_graph()
+    else:
+        release = get_releases(RELEASE_TO_BRANCH[release_type])[-1]
+        previous_graph = get_release_graph(release)
+    existing_tasks = find_existing_tasks([previous_graph])
+
+    previous_parameters = Parameters(
+        strict=False, **get_artifact(previous_graph, "public/parameters.yml")
+    )
+
+    # Copy L10n configuration from the commit the release we are using was
+    # based on. This *should* ensure that the chunking of L10n tasks is the
+    # same between graphs.
+    files_to_change = {
+        path: get_hg_file(previous_parameters, path)
+        for path in [
+            "browser/locales/l10n-changesets.json",
+            "browser/locales/shipped-locales",
+        ]
+    }
+
+    try_config = try_config or {}
+    task_config = {
+        "version": 2,
+        "parameters": {
+            "existing_tasks": existing_tasks,
+            "try_task_config": try_config,
+            "try_mode": "try_task_config",
+        },
+    }
+    for param in (
+        "app_version",
+        "build_number",
+        "next_version",
+        "release_history",
+        "release_product",
+        "release_type",
+        "version",
+    ):
+        task_config["parameters"][param] = previous_parameters[param]
+
+    try_config["tasks"] = TASK_TYPES[task_type]
+    for label in try_config["tasks"]:
+        if label in existing_tasks:
+            del existing_tasks[label]
+
+    msg = "scriptworker tests: {}".format(task_type)
+    return push_to_try(
+        "scriptworker",
+        message.format(msg=msg),
+        stage_changes=stage_changes,
+        dry_run=dry_run,
+        closed_tree=closed_tree,
+        try_task_config=task_config,
+        files_to_change=files_to_change,
+    )
diff --git a/tools/tryselect/selectors/syntax.py b/tools/tryselect/selectors/syntax.py
new file mode 100644
index 0000000000..ad643f8314
--- /dev/null
+++ b/tools/tryselect/selectors/syntax.py
@@ -0,0 +1,708 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+import os
+import re
+import sys
+from collections import defaultdict
+
+import mozpack.path as mozpath
+from moztest.resolve import TestResolver
+
+from ..cli import BaseTryParser
+from ..push import build, push_to_try
+
+here = os.path.abspath(os.path.dirname(__file__))
+
+
+class SyntaxParser(BaseTryParser):
+    name = "syntax"
+    arguments = [
+        [
+            ["paths"],
+            {
+                "nargs": "*",
+                "default": [],
+                "help": "Paths to search for tests to run on try.",
+            },
+        ],
+        [
+            ["-b", "--build"],
+            {
+                "dest": "builds",
+                "default": "do",
+                "help": "Build types to run (d for debug, o for optimized).",
+            },
+        ],
+        [
+            ["-p", "--platform"],
+            {
+                "dest": "platforms",
+                "action": "append",
+                "help": "Platforms to run (required if not found in the environment as "
+                "AUTOTRY_PLATFORM_HINT).",
+            },
+        ],
+        [
+            ["-u", "--unittests"],
+            {
+                "dest": "tests",
+                "action": "append",
+                "help": "Test suites to run in their entirety.",
+            },
+        ],
+        [
+            ["-t", "--talos"],
+            {
+                "action": "append",
+                "help": "Talos suites to run.",
+            },
+        ],
+        [
+            ["-j", "--jobs"],
+            {
+                "action": "append",
+                "help": "Job tasks to run.",
+            },
+        ],
+        [
+            ["--tag"],
+            {
+                "dest": "tags",
+                "action": "append",
+                "help": "Restrict tests to the given tag (may be specified multiple times).",
+            },
+        ],
+        [
+            ["--and"],
+            {
+                "action": "store_true",
+                "dest": "intersection",
+                "help": "When -u and paths are supplied run only the intersection of the "
+                "tests specified by the two arguments.",
+            },
+        ],
+        [
+            ["--no-artifact"],
+            {
+                "action": "store_true",
+                "help": "Disable artifact builds even if --enable-artifact-builds is set "
+                "in the mozconfig.",
+            },
+        ],
+        [
+            ["-v", "--verbose"],
+            {
+                "dest": "verbose",
+                "action": "store_true",
+                "default": False,
+                "help": "Print detailed information about the resulting test selection "
+                "and commands performed.",
+            },
+        ],
+    ]
+
+    # Arguments we will accept on the command line and pass through to try
+    # syntax with no further intervention. The set is taken from
+    # http://trychooser.pub.build.mozilla.org with a few additions.
+    #
+    # Note that the meaning of store_false and store_true arguments is
+    # not preserved here, as we're only using these to echo the literal
+    # arguments to another consumer. Specifying either store_false or
+    # store_true here will have an equivalent effect.
+    pass_through_arguments = {
+        "--rebuild": {
+            "action": "store",
+            "dest": "rebuild",
+            "help": "Re-trigger all test jobs (up to 20 times)",
+        },
+        "--rebuild-talos": {
+            "action": "store",
+            "dest": "rebuild_talos",
+            "help": "Re-trigger all talos jobs",
+        },
+        "--interactive": {
+            "action": "store_true",
+            "dest": "interactive",
+            "help": "Allow ssh-like access to running test containers",
+        },
+        "--no-retry": {
+            "action": "store_true",
+            "dest": "no_retry",
+            "help": "Do not retrigger failed tests",
+        },
+        "--setenv": {
+            "action": "append",
+            "dest": "setenv",
+            "help": "Set the corresponding variable in the test environment for "
+            "applicable harnesses.",
+        },
+        "-f": {
+            "action": "store_true",
+            "dest": "failure_emails",
+            "help": "Request failure emails only",
+        },
+        "--failure-emails": {
+            "action": "store_true",
+            "dest": "failure_emails",
+            "help": "Request failure emails only",
+        },
+        "-e": {
+            "action": "store_true",
+            "dest": "all_emails",
+            "help": "Request all emails",
+        },
+        "--all-emails": {
+            "action": "store_true",
+            "dest": "all_emails",
+            "help": "Request all emails",
+        },
+        "--artifact": {
+            "action": "store_true",
+            "dest": "artifact",
+            "help": "Force artifact builds where possible.",
+        },
+        "--upload-xdbs": {
+            "action": "store_true",
+            "dest": "upload_xdbs",
+            "help": "Upload XDB compilation db files generated by hazard build",
+        },
+    }
+    task_configs = []
+
+    def __init__(self, *args, **kwargs):
+        BaseTryParser.__init__(self, *args, **kwargs)
+
+        group = self.add_argument_group("pass-through arguments")
+        for arg, opts in self.pass_through_arguments.items():
+            group.add_argument(arg, **opts)
+
+
+class TryArgumentTokenizer:
+    symbols = [
+        ("separator", ","),
+        ("list_start", r"\["),
+        ("list_end", r"\]"),
+        ("item", r"([^,\[\]\s][^,\[\]]+)"),
+        ("space", r"\s+"),
+    ]
+    token_re = re.compile("|".join("(?P<%s>%s)" % item for item in symbols))
+
+    def tokenize(self, data):
+        for match in self.token_re.finditer(data):
+            symbol = match.lastgroup
+            data = match.group(symbol)
+            if symbol == "space":
+                pass
+            else:
+                yield symbol, data
+
+
+class TryArgumentParser:
+    """Simple three-state parser for handling expressions
+    of the from "foo[sub item, another], bar,baz". This takes
+    input from the TryArgumentTokenizer and runs through a small
+    state machine, returning a dictionary of {top-level-item:[sub_items]}
+    i.e. the above would result in
+    {"foo":["sub item", "another"], "bar": [], "baz": []}
+    In the case of invalid input a ValueError is raised."""
+
+    EOF = object()
+
+    def __init__(self):
+        self.reset()
+
+    def reset(self):
+        self.tokens = None
+        self.current_item = None
+        self.data = {}
+        self.token = None
+        self.state = None
+
+    def parse(self, tokens):
+        self.reset()
+        self.tokens = tokens
+        self.consume()
+        self.state = self.item_state
+        while self.token[0] != self.EOF:
+            self.state()
+        return self.data
+
+    def consume(self):
+        try:
+            self.token = next(self.tokens)
+        except StopIteration:
+            self.token = (self.EOF, None)
+
+    def expect(self, *types):
+        if self.token[0] not in types:
+            raise ValueError(
+                "Error parsing try string, unexpected %s" % (self.token[0])
+            )
+
+    def item_state(self):
+        self.expect("item")
+        value = self.token[1].strip()
+        if value not in self.data:
+            self.data[value] = []
+        self.current_item = value
+        self.consume()
+        if self.token[0] == "separator":
+            self.consume()
+        elif self.token[0] == "list_start":
+            self.consume()
+            self.state = self.subitem_state
+        elif self.token[0] == self.EOF:
+            pass
+        else:
+            raise ValueError
+
+    def subitem_state(self):
+        self.expect("item")
+        value = self.token[1].strip()
+        self.data[self.current_item].append(value)
+        self.consume()
+        if self.token[0] == "separator":
+            self.consume()
+        elif self.token[0] == "list_end":
+            self.consume()
+            self.state = self.after_list_end_state
+        else:
+            raise ValueError
+
+    def after_list_end_state(self):
+        self.expect("separator")
+        self.consume()
+        self.state = self.item_state
+
+
+def parse_arg(arg):
+    tokenizer = TryArgumentTokenizer()
+    parser = TryArgumentParser()
+    return parser.parse(tokenizer.tokenize(arg))
+
+
+class AutoTry:
+
+    # Maps from flavors to the job names needed to run that flavour
+    flavor_jobs = {
+        "mochitest": ["mochitest-1", "mochitest-e10s-1"],
+        "xpcshell": ["xpcshell"],
+        "chrome": ["mochitest-o"],
+        "browser-a11y": ["mochitest-ba"],
+        "browser-media": ["mochitest-bmda"],
+        "browser-chrome": [
+            "mochitest-browser-chrome-1",
+            "mochitest-e10s-browser-chrome-1",
+            "mochitest-browser-chrome-e10s-1",
+        ],
+        "devtools-chrome": [
+            "mochitest-devtools-chrome-1",
+            "mochitest-e10s-devtools-chrome-1",
+            "mochitest-devtools-chrome-e10s-1",
+        ],
+        "crashtest": ["crashtest", "crashtest-e10s"],
+        "reftest": ["reftest", "reftest-e10s"],
+        "remote": ["mochitest-remote"],
+        "web-platform-tests": ["web-platform-tests-1"],
+    }
+
+    flavor_suites = {
+        "mochitest": "mochitests",
+        "xpcshell": "xpcshell",
+        "chrome": "mochitest-o",
+        "browser-chrome": "mochitest-bc",
+        "browser-a11y": "mochitest-ba",
+        "browser-media": "mochitest-bmda",
+        "devtools-chrome": "mochitest-dt",
+        "crashtest": "crashtest",
+        "reftest": "reftest",
+        "web-platform-tests": "web-platform-tests",
+    }
+
+    compiled_suites = [
+        "cppunit",
+        "gtest",
+        "jittest",
+    ]
+
+    common_suites = [
+        "cppunit",
+        "crashtest",
+        "firefox-ui-functional",
+        "geckoview",
+        "geckoview-junit",
+        "gtest",
+        "jittest",
+        "jsreftest",
+        "marionette",
+        "marionette-e10s",
+        "mochitests",
+        "reftest",
+        "robocop",
+        "web-platform-tests",
+        "xpcshell",
+    ]
+
+    def __init__(self):
+        self.topsrcdir = build.topsrcdir
+        self._resolver = None
+
+    @property
+    def resolver(self):
+        if self._resolver is None:
+            self._resolver = TestResolver.from_environment(cwd=here)
+        return self._resolver
+
+    @classmethod
+    def split_try_string(cls, data):
+        return re.findall(r"(?:\[.*?\]|\S)+", data)
+
+    def paths_by_flavor(self, paths=None, tags=None):
+        paths_by_flavor = defaultdict(set)
+
+        if not (paths or tags):
+            return dict(paths_by_flavor)
+
+        tests = list(self.resolver.resolve_tests(paths=paths, tags=tags))
+
+        for t in tests:
+            if t["flavor"] in self.flavor_suites:
+                flavor = t["flavor"]
+                if "subsuite" in t and t["subsuite"] == "devtools":
+                    flavor = "devtools-chrome"
+
+                if "subsuite" in t and t["subsuite"] == "a11y":
+                    flavor = "browser-a11y"
+
+                if "subsuite" in t and t["subsuite"] == "media-bc":
+                    flavor = "browser-media"
+
+                if flavor in ["crashtest", "reftest"]:
+                    manifest_relpath = os.path.relpath(t["manifest"], self.topsrcdir)
+                    paths_by_flavor[flavor].add(os.path.dirname(manifest_relpath))
+                elif "dir_relpath" in t:
+                    paths_by_flavor[flavor].add(t["dir_relpath"])
+                else:
+                    file_relpath = os.path.relpath(t["path"], self.topsrcdir)
+                    dir_relpath = os.path.dirname(file_relpath)
+                    paths_by_flavor[flavor].add(dir_relpath)
+
+        for flavor, path_set in paths_by_flavor.items():
+            paths_by_flavor[flavor] = self.deduplicate_prefixes(path_set, paths)
+
+        return dict(paths_by_flavor)
+
+    def deduplicate_prefixes(self, path_set, input_paths):
+        # Removes paths redundant to test selection in the given path set.
+        # If a path was passed on the commandline that is the prefix of a
+        # path in our set, we only need to include the specified prefix to
+        # run the intended tests (every test in "layout/base" will run if
+        # "layout" is passed to the reftest harness).
+        removals = set()
+        additions = set()
+
+        for path in path_set:
+            full_path = path
+            while path:
+                path, _ = os.path.split(path)
+                if path in input_paths:
+                    removals.add(full_path)
+                    additions.add(path)
+
+        return additions | (path_set - removals)
+
+    def remove_duplicates(self, paths_by_flavor, tests):
+        rv = {}
+        for item in paths_by_flavor:
+            if self.flavor_suites[item] not in tests:
+                rv[item] = paths_by_flavor[item].copy()
+        return rv
+
+    def calc_try_syntax(
+        self,
+        platforms,
+        tests,
+        talos,
+        jobs,
+        builds,
+        paths_by_flavor,
+        tags,
+        extras,
+        intersection,
+    ):
+        parts = ["try:"]
+
+        if platforms:
+            parts.extend(["-b", builds, "-p", ",".join(platforms)])
+
+        suites = tests if not intersection else {}
+        paths = set()
+        for flavor, flavor_tests in paths_by_flavor.items():
+            suite = self.flavor_suites[flavor]
+            if suite not in suites and (not intersection or suite in tests):
+                for job_name in self.flavor_jobs[flavor]:
+                    for test in flavor_tests:
+                        paths.add("{}:{}".format(flavor, test))
+                    suites[job_name] = tests.get(suite, [])
+
+        # intersection implies tests are expected
+        if intersection and not suites:
+            raise ValueError("No tests found matching filters")
+
+        if extras.get("artifact") and any([p.endswith("-nightly") for p in platforms]):
+            print(
+                'You asked for |--artifact| but "-nightly" platforms don\'t have artifacts. '
+                "Running without |--artifact| instead."
+            )
+            del extras["artifact"]
+
+        if extras.get("artifact"):
+            rejected = []
+            for suite in suites.keys():
+                if any([suite.startswith(c) for c in self.compiled_suites]):
+                    rejected.append(suite)
+            if rejected:
+                raise ValueError(
+                    "You can't run {} with "
+                    "--artifact option.".format(", ".join(rejected))
+                )
+
+        if extras.get("artifact") and "all" in suites.keys():
+            non_compiled_suites = set(self.common_suites) - set(self.compiled_suites)
+            message = (
+                "You asked for |-u all| with |--artifact| but compiled-code tests ({tests})"
+                " can't run against an artifact build. Running (-u {non_compiled_suites}) "
+                "instead."
+            )
+            string_format = {
+                "tests": ",".join(self.compiled_suites),
+                "non_compiled_suites": ",".join(non_compiled_suites),
+            }
+            print(message.format(**string_format))
+            del suites["all"]
+            suites.update({suite_name: None for suite_name in non_compiled_suites})
+
+        if suites:
+            parts.append("-u")
+            parts.append(
+                ",".join(
+                    "{}{}".format(k, "[%s]" % ",".join(v) if v else "")
+                    for k, v in sorted(suites.items())
+                )
+            )
+
+        if talos:
+            parts.append("-t")
+            parts.append(
+                ",".join(
+                    "{}{}".format(k, "[%s]" % ",".join(v) if v else "")
+                    for k, v in sorted(talos.items())
+                )
+            )
+
+        if jobs:
+            parts.append("-j")
+            parts.append(",".join(jobs))
+
+        if tags:
+            parts.append(" ".join("--tag %s" % t for t in tags))
+
+        if paths:
+            parts.append("--try-test-paths %s" % " ".join(sorted(paths)))
+
+        args_by_dest = {
+            v["dest"]: k for k, v in SyntaxParser.pass_through_arguments.items()
+        }
+        for dest, value in extras.items():
+            assert dest in args_by_dest
+            arg = args_by_dest[dest]
+            action = SyntaxParser.pass_through_arguments[arg]["action"]
+            if action == "store":
+                parts.append(arg)
+                parts.append(value)
+            if action == "append":
+                for e in value:
+                    parts.append(arg)
+                    parts.append(e)
+            if action in ("store_true", "store_false"):
+                parts.append(arg)
+
+        return " ".join(parts)
+
+    def normalise_list(self, items, allow_subitems=False):
+        rv = defaultdict(list)
+        for item in items:
+            parsed = parse_arg(item)
+            for key, values in parsed.items():
+                rv[key].extend(values)
+
+        if not allow_subitems:
+            if not all(item == [] for item in rv.values()):
+                raise ValueError("Unexpected subitems in argument")
+            return rv.keys()
+        else:
+            return rv
+
+    def validate_args(self, **kwargs):
+        tests_selected = kwargs["tests"] or kwargs["paths"] or kwargs["tags"]
+        if kwargs["platforms"] is None and (kwargs["jobs"] is None or tests_selected):
+            if "AUTOTRY_PLATFORM_HINT" in os.environ:
+                kwargs["platforms"] = [os.environ["AUTOTRY_PLATFORM_HINT"]]
+            elif tests_selected:
+                print("Must specify platform when selecting tests.")
+                sys.exit(1)
+            else:
+                print(
+                    "Either platforms or jobs must be specified as an argument to autotry."
+                )
+                sys.exit(1)
+
+        try:
+            platforms = (
+                self.normalise_list(kwargs["platforms"]) if kwargs["platforms"] else {}
+            )
+        except ValueError as e:
+            print("Error parsing -p argument:\n%s" % e)
+            sys.exit(1)
+
+        try:
+            tests = (
+                self.normalise_list(kwargs["tests"], allow_subitems=True)
+                if kwargs["tests"]
+                else {}
+            )
+        except ValueError as e:
+            print("Error parsing -u argument ({}):\n{}".format(kwargs["tests"], e))
+            sys.exit(1)
+
+        try:
+            talos = (
+                self.normalise_list(kwargs["talos"], allow_subitems=True)
+                if kwargs["talos"]
+                else []
+            )
+        except ValueError as e:
+            print("Error parsing -t argument:\n%s" % e)
+            sys.exit(1)
+
+        try:
+            jobs = self.normalise_list(kwargs["jobs"]) if kwargs["jobs"] else {}
+        except ValueError as e:
+            print("Error parsing -j argument:\n%s" % e)
+            sys.exit(1)
+
+        paths = []
+        for p in kwargs["paths"]:
+            p = mozpath.normpath(os.path.abspath(p))
+            if not (os.path.isdir(p) and p.startswith(self.topsrcdir)):
+                print(
+                    'Specified path "%s" is not a directory under the srcdir,'
+                    " unable to specify tests outside of the srcdir" % p
+                )
+                sys.exit(1)
+            if len(p) <= len(self.topsrcdir):
+                print(
+                    'Specified path "%s" is at the top of the srcdir and would'
+                    " select all tests." % p
+                )
+                sys.exit(1)
+            paths.append(os.path.relpath(p, self.topsrcdir))
+
+        try:
+            tags = self.normalise_list(kwargs["tags"]) if kwargs["tags"] else []
+        except ValueError as e:
+            print("Error parsing --tags argument:\n%s" % e)
+            sys.exit(1)
+
+        extra_values = {k["dest"] for k in SyntaxParser.pass_through_arguments.values()}
+        extra_args = {k: v for k, v in kwargs.items() if k in extra_values and v}
+
+        return kwargs["builds"], platforms, tests, talos, jobs, paths, tags, extra_args
+
+    def run(self, **kwargs):
+        if not any(kwargs[item] for item in ("paths", "tests", "tags")):
+            kwargs["paths"] = set()
+            kwargs["tags"] = set()
+
+        builds, platforms, tests, talos, jobs, paths, tags, extra = self.validate_args(
+            **kwargs
+        )
+
+        if paths or tags:
+            paths = [
+                os.path.relpath(os.path.normpath(os.path.abspath(item)), self.topsrcdir)
+                for item in paths
+            ]
+            paths_by_flavor = self.paths_by_flavor(paths=paths, tags=tags)
+
+            if not paths_by_flavor and not tests:
+                print(
+                    "No tests were found when attempting to resolve paths:\n\n\t%s"
+                    % paths
+                )
+                sys.exit(1)
+
+            if not kwargs["intersection"]:
+                paths_by_flavor = self.remove_duplicates(paths_by_flavor, tests)
+        else:
+            paths_by_flavor = {}
+
+        # No point in dealing with artifacts if we aren't running any builds
+        local_artifact_build = False
+        if platforms:
+            local_artifact_build = kwargs.get("local_artifact_build", False)
+
+            # Add --artifact if --enable-artifact-builds is set ...
+            if local_artifact_build:
+                extra["artifact"] = True
+            # ... unless --no-artifact is explicitly given.
+            if kwargs["no_artifact"]:
+                if "artifact" in extra:
+                    del extra["artifact"]
+
+        try:
+            msg = self.calc_try_syntax(
+                platforms,
+                tests,
+                talos,
+                jobs,
+                builds,
+                paths_by_flavor,
+                tags,
+                extra,
+                kwargs["intersection"],
+            )
+        except ValueError as e:
+            print(e)
+            sys.exit(1)
+
+        if local_artifact_build and not kwargs["no_artifact"]:
+            print(
+                "mozconfig has --enable-artifact-builds; including "
+                "--artifact flag in try syntax (use --no-artifact "
+                "to override)"
+            )
+
+        if kwargs["verbose"] and paths_by_flavor:
+            print("The following tests will be selected: ")
+            for flavor, paths in paths_by_flavor.items():
+                print("{}: {}".format(flavor, ",".join(paths)))
+
+        if kwargs["verbose"]:
+            print("The following try syntax was calculated:\n%s" % msg)
+
+        push_to_try(
+            "syntax",
+            kwargs["message"].format(msg=msg),
+            stage_changes=kwargs["stage_changes"],
+            dry_run=kwargs["dry_run"],
+            closed_tree=kwargs["closed_tree"],
+        )
+
+
+def run(**kwargs):
+    at = AutoTry()
+    return at.run(**kwargs)
diff --git a/tools/tryselect/task_config.py b/tools/tryselect/task_config.py
new file mode 100644
index 0000000000..5db1f9c90d
--- /dev/null
+++ b/tools/tryselect/task_config.py
@@ -0,0 +1,530 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+"""
+Templates provide a way of modifying the task definition of selected tasks.
+They are added to 'try_task_config.json' and processed by the transforms.
+"""
+
+
+import json
+import os
+import subprocess
+import sys
+from abc import ABCMeta, abstractmethod, abstractproperty
+from argparse import SUPPRESS, Action
+from textwrap import dedent
+
+import mozpack.path as mozpath
+import six
+from mozbuild.base import BuildEnvironmentNotFoundException, MozbuildObject
+
+from .tasks import resolve_tests_by_suite
+
+here = os.path.abspath(os.path.dirname(__file__))
+build = MozbuildObject.from_environment(cwd=here)
+
+
+class TryConfig:
+    __metaclass__ = ABCMeta
+
+    def __init__(self):
+        self.dests = set()
+
+    def add_arguments(self, parser):
+        for cli, kwargs in self.arguments:
+            action = parser.add_argument(*cli, **kwargs)
+            self.dests.add(action.dest)
+
+    @abstractproperty
+    def arguments(self):
+        pass
+
+    @abstractmethod
+    def try_config(self, **kwargs):
+        pass
+
+    def validate(self, **kwargs):
+        pass
+
+
+class Artifact(TryConfig):
+
+    arguments = [
+        [
+            ["--artifact"],
+            {"action": "store_true", "help": "Force artifact builds where possible."},
+        ],
+        [
+            ["--no-artifact"],
+            {
+                "action": "store_true",
+                "help": "Disable artifact builds even if being used locally.",
+            },
+        ],
+    ]
+
+    def add_arguments(self, parser):
+        group = parser.add_mutually_exclusive_group()
+        return super().add_arguments(group)
+
+    @classmethod
+    def is_artifact_build(cls):
+        try:
+            return build.substs.get("MOZ_ARTIFACT_BUILDS", False)
+        except BuildEnvironmentNotFoundException:
+            return False
+
+    def try_config(self, artifact, no_artifact, **kwargs):
+        if artifact:
+            return {"use-artifact-builds": True}
+
+        if no_artifact:
+            return
+
+        if self.is_artifact_build():
+            print("Artifact builds enabled, pass --no-artifact to disable")
+            return {"use-artifact-builds": True}
+
+
+class Pernosco(TryConfig):
+    arguments = [
+        [
+            ["--pernosco"],
+            {
+                "action": "store_true",
+                "default": None,
+                "help": "Opt-in to analysis by the Pernosco debugging service.",
+            },
+        ],
+        [
+            ["--no-pernosco"],
+            {
+                "dest": "pernosco",
+                "action": "store_false",
+                "default": None,
+                "help": "Opt-out of the Pernosco debugging service (if you are on the whitelist).",
+            },
+        ],
+    ]
+
+    def add_arguments(self, parser):
+        group = parser.add_mutually_exclusive_group()
+        return super().add_arguments(group)
+
+    def try_config(self, pernosco, **kwargs):
+        if pernosco is None:
+            return
+
+        if pernosco:
+            try:
+                # The Pernosco service currently requires a Mozilla e-mail address to
+                # log in. Prevent people with non-Mozilla addresses from using this
+                # flag so they don't end up consuming time and resources only to
+                # realize they can't actually log in and see the reports.
+                cmd = ["ssh", "-G", "hg.mozilla.org"]
+                output = subprocess.check_output(
+                    cmd, universal_newlines=True
+                ).splitlines()
+                address = [
+                    l.rsplit(" ", 1)[-1] for l in output if l.startswith("user")
+                ][0]
+                if not address.endswith("@mozilla.com"):
+                    print(
+                        dedent(
+                            """\
+                        Pernosco requires a Mozilla e-mail address to view its reports. Please
+                        push to try with an @mozilla.com address to use --pernosco.
+
+                            Current user: {}
+                    """.format(
+                                address
+                            )
+                        )
+                    )
+                    sys.exit(1)
+
+            except (subprocess.CalledProcessError, IndexError):
+                print("warning: failed to detect current user for 'hg.mozilla.org'")
+                print("Pernosco requires a Mozilla e-mail address to view its reports.")
+                while True:
+                    answer = input(
+                        "Do you have an @mozilla.com address? [Y/n]: "
+                    ).lower()
+                    if answer == "n":
+                        sys.exit(1)
+                    elif answer == "y":
+                        break
+
+        return {
+            "env": {
+                "PERNOSCO": str(int(pernosco)),
+            }
+        }
+
+    def validate(self, **kwargs):
+        if kwargs["try_config"].get("use-artifact-builds"):
+            print(
+                "Pernosco does not support artifact builds at this time. "
+                "Please try again with '--no-artifact'."
+            )
+            sys.exit(1)
+
+
+class Path(TryConfig):
+
+    arguments = [
+        [
+            ["paths"],
+            {
+                "nargs": "*",
+                "default": [],
+                "help": "Run tasks containing tests under the specified path(s).",
+            },
+        ],
+    ]
+
+    def try_config(self, paths, **kwargs):
+        if not paths:
+            return
+
+        for p in paths:
+            if not os.path.exists(p):
+                print("error: '{}' is not a valid path.".format(p), file=sys.stderr)
+                sys.exit(1)
+
+        paths = [
+            mozpath.relpath(mozpath.join(os.getcwd(), p), build.topsrcdir)
+            for p in paths
+        ]
+        return {
+            "env": {
+                "MOZHARNESS_TEST_PATHS": six.ensure_text(
+                    json.dumps(resolve_tests_by_suite(paths))
+                ),
+            }
+        }
+
+
+class Environment(TryConfig):
+
+    arguments = [
+        [
+            ["--env"],
+            {
+                "action": "append",
+                "default": None,
+                "help": "Set an environment variable, of the form FOO=BAR. "
+                "Can be passed in multiple times.",
+            },
+        ],
+    ]
+
+    def try_config(self, env, **kwargs):
+        if not env:
+            return
+        return {
+            "env": dict(e.split("=", 1) for e in env),
+        }
+
+
+class RangeAction(Action):
+    def __init__(self, min, max, *args, **kwargs):
+        self.min = min
+        self.max = max
+        kwargs["metavar"] = "[{}-{}]".format(self.min, self.max)
+        super().__init__(*args, **kwargs)
+
+    def __call__(self, parser, namespace, values, option_string=None):
+        name = option_string or self.dest
+        if values < self.min:
+            parser.error("{} can not be less than {}".format(name, self.min))
+        if values > self.max:
+            parser.error("{} can not be more than {}".format(name, self.max))
+        setattr(namespace, self.dest, values)
+
+
+class Rebuild(TryConfig):
+
+    arguments = [
+        [
+            ["--rebuild"],
+            {
+                "action": RangeAction,
+                "min": 2,
+                "max": 20,
+                "default": None,
+                "type": int,
+                "help": "Rebuild all selected tasks the specified number of times.",
+            },
+        ],
+    ]
+
+    def try_config(self, rebuild, **kwargs):
+        if not rebuild:
+            return
+
+        if kwargs.get("full") and rebuild > 3:
+            print(
+                "warning: limiting --rebuild to 3 when using --full. "
+                "Use custom push actions to add more."
+            )
+            rebuild = 3
+
+        return {
+            "rebuild": rebuild,
+        }
+
+
+class Routes(TryConfig):
+    arguments = [
+        [
+            ["--route"],
+            {
+                "action": "append",
+                "dest": "routes",
+                "help": (
+                    "Additional route to add to the tasks "
+                    "(note: these will not be added to the decision task)"
+                ),
+            },
+        ],
+    ]
+
+    def try_config(self, routes, **kwargs):
+        if routes:
+            return {
+                "routes": routes,
+            }
+
+
+class ChemspillPrio(TryConfig):
+
+    arguments = [
+        [
+            ["--chemspill-prio"],
+            {
+                "action": "store_true",
+                "help": "Run at a higher priority than most try jobs (chemspills only).",
+            },
+        ],
+    ]
+
+    def try_config(self, chemspill_prio, **kwargs):
+        if chemspill_prio:
+            return {"chemspill-prio": {}}
+
+
+class GeckoProfile(TryConfig):
+    arguments = [
+        [
+            ["--gecko-profile"],
+            {
+                "dest": "profile",
+                "action": "store_true",
+                "default": False,
+                "help": "Create and upload a gecko profile during talos/raptor tasks.",
+            },
+        ],
+        [
+            ["--gecko-profile-interval"],
+            {
+                "dest": "gecko_profile_interval",
+                "type": float,
+                "help": "How frequently to take samples (ms)",
+            },
+        ],
+        [
+            ["--gecko-profile-entries"],
+            {
+                "dest": "gecko_profile_entries",
+                "type": int,
+                "help": "How many samples to take with the profiler",
+            },
+        ],
+        [
+            ["--gecko-profile-features"],
+            {
+                "dest": "gecko_profile_features",
+                "type": str,
+                "default": None,
+                "help": "Set the features enabled for the profiler.",
+            },
+        ],
+        [
+            ["--gecko-profile-threads"],
+            {
+                "dest": "gecko_profile_threads",
+                "type": str,
+                "help": "Comma-separated list of threads to sample.",
+            },
+        ],
+        # For backwards compatibility
+        [
+            ["--talos-profile"],
+            {
+                "dest": "profile",
+                "action": "store_true",
+                "default": False,
+                "help": SUPPRESS,
+            },
+        ],
+        # This is added for consistency with the 'syntax' selector
+        [
+            ["--geckoProfile"],
+            {
+                "dest": "profile",
+                "action": "store_true",
+                "default": False,
+                "help": SUPPRESS,
+            },
+        ],
+    ]
+
+    def try_config(
+        self,
+        profile,
+        gecko_profile_interval,
+        gecko_profile_entries,
+        gecko_profile_features,
+        gecko_profile_threads,
+        **kwargs
+    ):
+        if profile or not all(
+            s is None for s in (gecko_profile_features, gecko_profile_threads)
+        ):
+            cfg = {
+                "gecko-profile": True,
+                "gecko-profile-interval": gecko_profile_interval,
+                "gecko-profile-entries": gecko_profile_entries,
+                "gecko-profile-features": gecko_profile_features,
+                "gecko-profile-threads": gecko_profile_threads,
+            }
+            return {key: value for key, value in cfg.items() if value is not None}
+
+
+class Browsertime(TryConfig):
+    arguments = [
+        [
+            ["--browsertime"],
+            {
+                "action": "store_true",
+                "help": "Use browsertime during Raptor tasks.",
+            },
+        ],
+    ]
+
+    def try_config(self, browsertime, **kwargs):
+        if browsertime:
+            return {
+                "browsertime": True,
+            }
+
+
+class DisablePgo(TryConfig):
+
+    arguments = [
+        [
+            ["--disable-pgo"],
+            {
+                "action": "store_true",
+                "help": "Don't run PGO builds",
+            },
+        ],
+    ]
+
+    def try_config(self, disable_pgo, **kwargs):
+        if disable_pgo:
+            return {
+                "disable-pgo": True,
+            }
+
+
+class WorkerOverrides(TryConfig):
+
+    arguments = [
+        [
+            ["--worker-override"],
+            {
+                "action": "append",
+                "dest": "worker_overrides",
+                "help": (
+                    "Override the worker pool used for a given taskgraph worker alias. "
+                    "The argument should be `<alias>=<worker-pool>`. "
+                    "Can be specified multiple times."
+                ),
+            },
+        ],
+        [
+            ["--worker-suffix"],
+            {
+                "action": "append",
+                "dest": "worker_suffixes",
+                "help": (
+                    "Override the worker pool used for a given taskgraph worker alias, "
+                    "by appending a suffix to the work-pool. "
+                    "The argument should be `<alias>=<suffix>`. "
+                    "Can be specified multiple times."
+                ),
+            },
+        ],
+    ]
+
+    def try_config(self, worker_overrides, worker_suffixes, **kwargs):
+        from gecko_taskgraph.util.workertypes import get_worker_type
+        from taskgraph.config import load_graph_config
+
+        overrides = {}
+        if worker_overrides:
+            for override in worker_overrides:
+                alias, worker_pool = override.split("=", 1)
+                if alias in overrides:
+                    print(
+                        "Can't override worker alias {alias} more than once. "
+                        "Already set to use {previous}, but also asked to use {new}.".format(
+                            alias=alias, previous=overrides[alias], new=worker_pool
+                        )
+                    )
+                    sys.exit(1)
+                overrides[alias] = worker_pool
+
+        if worker_suffixes:
+            root = build.topsrcdir
+            root = os.path.join(root, "taskcluster", "ci")
+            graph_config = load_graph_config(root)
+            for worker_suffix in worker_suffixes:
+                alias, suffix = worker_suffix.split("=", 1)
+                if alias in overrides:
+                    print(
+                        "Can't override worker alias {alias} more than once. "
+                        "Already set to use {previous}, but also asked "
+                        "to add suffix {suffix}.".format(
+                            alias=alias, previous=overrides[alias], suffix=suffix
+                        )
+                    )
+                    sys.exit(1)
+                provisioner, worker_type = get_worker_type(
+                    graph_config, worker_type=alias, parameters={"level": "1"}
+                )
+                overrides[alias] = "{provisioner}/{worker_type}{suffix}".format(
+                    provisioner=provisioner, worker_type=worker_type, suffix=suffix
+                )
+
+        if overrides:
+            return {"worker-overrides": overrides}
+
+
+all_task_configs = {
+    "artifact": Artifact,
+    "browsertime": Browsertime,
+    "chemspill-prio": ChemspillPrio,
+    "disable-pgo": DisablePgo,
+    "env": Environment,
+    "gecko-profile": GeckoProfile,
+    "path": Path,
+    "pernosco": Pernosco,
+    "rebuild": Rebuild,
+    "routes": Routes,
+    "worker-overrides": WorkerOverrides,
+}
diff --git a/tools/tryselect/tasks.py b/tools/tryselect/tasks.py
new file mode 100644
index 0000000000..bca6b3de1b
--- /dev/null
+++ b/tools/tryselect/tasks.py
@@ -0,0 +1,186 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+import json
+import os
+import re
+import sys
+from collections import defaultdict
+
+import mozpack.path as mozpath
+import taskgraph
+from mach.util import get_state_dir
+from mozbuild.base import MozbuildObject
+from mozpack.files import FileFinder
+from moztest.resolve import TestManifestLoader, TestResolver, get_suite_definition
+from taskgraph.generator import TaskGraphGenerator
+from taskgraph.parameters import ParameterMismatch, parameters_loader
+from taskgraph.taskgraph import TaskGraph
+
+here = os.path.abspath(os.path.dirname(__file__))
+build = MozbuildObject.from_environment(cwd=here)
+
+PARAMETER_MISMATCH = """
+ERROR - The parameters being used to generate tasks differ from those expected
+by your working copy:
+
+    {}
+
+To fix this, either rebase onto the latest mozilla-central or pass in
+-p/--parameters. For more information on how to define parameters, see:
+https://firefox-source-docs.mozilla.org/taskcluster/taskcluster/mach.html#parameters
+"""
+
+
+def invalidate(cache):
+    try:
+        cmod = os.path.getmtime(cache)
+    except OSError as e:
+        # File does not exist. We catch OSError rather than use `isfile`
+        # because the recommended watchman hook could possibly invalidate the
+        # cache in-between the check to `isfile` and the call to `getmtime`
+        # below.
+        if e.errno == 2:
+            return
+        raise
+
+    tc_dir = os.path.join(build.topsrcdir, "taskcluster")
+    tmod = max(os.path.getmtime(os.path.join(tc_dir, p)) for p, _ in FileFinder(tc_dir))
+
+    if tmod > cmod:
+        os.remove(cache)
+
+
+def cache_key(attr, params, disable_target_task_filter):
+    key = attr
+    if params and params["project"] not in ("autoland", "mozilla-central"):
+        key += f"-{params['project']}"
+
+    if disable_target_task_filter and "full" not in attr:
+        key += "-uncommon"
+    return key
+
+
+def generate_tasks(params=None, full=False, disable_target_task_filter=False):
+    attr = "full_task_set" if full else "target_task_set"
+    target_tasks_method = (
+        "try_select_tasks"
+        if not disable_target_task_filter
+        else "try_select_tasks_uncommon"
+    )
+    params = parameters_loader(
+        params,
+        strict=False,
+        overrides={
+            "try_mode": "try_select",
+            "target_tasks_method": target_tasks_method,
+        },
+    )
+    root = os.path.join(build.topsrcdir, "taskcluster", "ci")
+    taskgraph.fast = True
+    generator = TaskGraphGenerator(root_dir=root, parameters=params)
+
+    cache_dir = os.path.join(
+        get_state_dir(specific_to_topsrcdir=True), "cache", "taskgraph"
+    )
+    key = cache_key(attr, generator.parameters, disable_target_task_filter)
+    cache = os.path.join(cache_dir, key)
+
+    invalidate(cache)
+    if os.path.isfile(cache):
+        with open(cache) as fh:
+            return TaskGraph.from_json(json.load(fh))[1]
+
+    if not os.path.isdir(cache_dir):
+        os.makedirs(cache_dir)
+
+    print("Task configuration changed, generating {}".format(attr.replace("_", " ")))
+
+    cwd = os.getcwd()
+    os.chdir(build.topsrcdir)
+
+    def generate(attr):
+        try:
+            tg = getattr(generator, attr)
+        except ParameterMismatch as e:
+            print(PARAMETER_MISMATCH.format(e.args[0]))
+            sys.exit(1)
+
+        # write cache
+        key = cache_key(attr, generator.parameters, disable_target_task_filter)
+        with open(os.path.join(cache_dir, key), "w") as fh:
+            json.dump(tg.to_json(), fh)
+        return tg
+
+    # Cache both full_task_set and target_task_set regardless of whether or not
+    # --full was requested. Caching is cheap and can potentially save a lot of
+    # time.
+    tg_full = generate("full_task_set")
+    tg_target = generate("target_task_set")
+
+    # discard results from these, we only need cache.
+    if full:
+        generate("full_task_graph")
+    generate("target_task_graph")
+
+    os.chdir(cwd)
+    if full:
+        return tg_full
+    return tg_target
+
+
+def filter_tasks_by_paths(tasks, paths):
+    resolver = TestResolver.from_environment(cwd=here, loader_cls=TestManifestLoader)
+    run_suites, run_tests = resolver.resolve_metadata(paths)
+    flavors = {(t["flavor"], t.get("subsuite")) for t in run_tests}
+
+    task_regexes = set()
+    for flavor, subsuite in flavors:
+        _, suite = get_suite_definition(flavor, subsuite, strict=True)
+        if "task_regex" not in suite:
+            print(
+                "warning: no tasks could be resolved from flavor '{}'{}".format(
+                    flavor, " and subsuite '{}'".format(subsuite) if subsuite else ""
+                )
+            )
+            continue
+
+        task_regexes.update(suite["task_regex"])
+
+    def match_task(task):
+        return any(re.search(pattern, task) for pattern in task_regexes)
+
+    return filter(match_task, tasks)
+
+
+def resolve_tests_by_suite(paths):
+    resolver = TestResolver.from_environment(cwd=here, loader_cls=TestManifestLoader)
+    _, run_tests = resolver.resolve_metadata(paths)
+
+    suite_to_tests = defaultdict(list)
+
+    # A dictionary containing all the input paths that we haven't yet
+    # assigned to a specific test flavor.
+    remaining_paths_by_suite = defaultdict(lambda: set(paths))
+
+    for test in run_tests:
+        key, _ = get_suite_definition(test["flavor"], test.get("subsuite"), strict=True)
+
+        test_path = test.get("srcdir_relpath")
+        if test_path is None:
+            continue
+        found_path = None
+        manifest_relpath = None
+        if "manifest_relpath" in test:
+            manifest_relpath = mozpath.normpath(test["manifest_relpath"])
+        for path in remaining_paths_by_suite[key]:
+            if test_path.startswith(path) or manifest_relpath == path:
+                found_path = path
+                break
+        if found_path:
+            suite_to_tests[key].append(found_path)
+            remaining_paths_by_suite[key].remove(found_path)
+
+    return suite_to_tests
diff --git a/tools/tryselect/test/conftest.py b/tools/tryselect/test/conftest.py
new file mode 100644
index 0000000000..7ffffc4b9b
--- /dev/null
+++ b/tools/tryselect/test/conftest.py
@@ -0,0 +1,101 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import os
+from unittest.mock import MagicMock
+
+import pytest
+import yaml
+from moztest.resolve import TestResolver
+from taskgraph.graph import Graph
+from taskgraph.task import Task
+from taskgraph.taskgraph import TaskGraph
+from tryselect import push
+
+
+@pytest.fixture
+def tg(request):
+    if not hasattr(request.module, "TASKS"):
+        pytest.fail(
+            "'tg' fixture used from a module that didn't define the TASKS variable"
+        )
+
+    tasks = request.module.TASKS
+    for task in tasks:
+        task.setdefault("task", {})
+        task["task"].setdefault("tags", {})
+
+    tasks = {t["label"]: Task(**t) for t in tasks}
+    return TaskGraph(tasks, Graph(tasks.keys(), set()))
+
+
+@pytest.fixture
+def patch_resolver(monkeypatch):
+    def inner(suites, tests):
+        def fake_test_metadata(*args, **kwargs):
+            return suites, tests
+
+        monkeypatch.setattr(TestResolver, "resolve_metadata", fake_test_metadata)
+
+    return inner
+
+
+@pytest.fixture(autouse=True)
+def patch_vcs(monkeypatch):
+    attrs = {
+        "path": push.vcs.path,
+    }
+    mock = MagicMock()
+    mock.configure_mock(**attrs)
+    monkeypatch.setattr(push, "vcs", mock)
+
+
+@pytest.fixture(scope="session")
+def run_mach():
+    import mach_initialize
+    from mach.config import ConfigSettings
+    from tryselect.tasks import build
+
+    mach = mach_initialize.initialize(build.topsrcdir)
+
+    def inner(args):
+        mach.settings = ConfigSettings()
+        return mach.run(args)
+
+    return inner
+
+
+def pytest_generate_tests(metafunc):
+    if all(
+        fixture in metafunc.fixturenames
+        for fixture in ("task_config", "args", "expected")
+    ):
+
+        def load_tests():
+            for task_config, tests in metafunc.module.TASK_CONFIG_TESTS.items():
+                for args, expected in tests:
+                    yield (task_config, args, expected)
+
+        tests = list(load_tests())
+        ids = ["{} {}".format(t[0], " ".join(t[1])).strip() for t in tests]
+        metafunc.parametrize("task_config,args,expected", tests, ids=ids)
+
+    elif all(
+        fixture in metafunc.fixturenames for fixture in ("shared_name", "shared_preset")
+    ):
+        preset_path = os.path.join(
+            push.build.topsrcdir, "tools", "tryselect", "try_presets.yml"
+        )
+        with open(preset_path, "r") as fh:
+            presets = list(yaml.safe_load(fh).items())
+
+        ids = [p[0] for p in presets]
+
+        # Mark fuzzy presets on Windows xfail due to fzf not being installed.
+        if os.name == "nt":
+            for i, preset in enumerate(presets):
+                if preset[1]["selector"] == "fuzzy":
+                    presets[i] = pytest.param(*preset, marks=pytest.mark.xfail)
+
+        metafunc.parametrize("shared_name,shared_preset", presets, ids=ids)
diff --git a/tools/tryselect/test/cram.ini b/tools/tryselect/test/cram.ini
new file mode 100644
index 0000000000..b1f0d8dfec
--- /dev/null
+++ b/tools/tryselect/test/cram.ini
@@ -0,0 +1,5 @@
+[test_auto.t]
+[test_empty.t]
+[test_fuzzy.t]
+[test_message.t]
+[test_preset.t]
diff --git a/tools/tryselect/test/python.ini b/tools/tryselect/test/python.ini
new file mode 100644
index 0000000000..b00b1d4adc
--- /dev/null
+++ b/tools/tryselect/test/python.ini
@@ -0,0 +1,18 @@
+[DEFAULT]
+subsuite=try
+
+[test_again.py]
+[test_auto.py]
+[test_chooser.py]
+requirements = tools/tryselect/selectors/chooser/requirements.txt
+[test_fuzzy.py]
+[test_mozharness_integration.py]
+[test_perf.py]
+[test_presets.py]
+# Modifies "task_duration_history.json" in .mozbuild. Since other tests depend on this file, this test
+# shouldn't be run in parallel with those other tests.
+sequential = true
+[test_release.py]
+[test_scriptworker.py]
+[test_tasks.py]
+[test_task_configs.py]
diff --git a/tools/tryselect/test/setup.sh b/tools/tryselect/test/setup.sh
new file mode 100644
index 0000000000..d9f3b62a2e
--- /dev/null
+++ b/tools/tryselect/test/setup.sh
@@ -0,0 +1,99 @@
+export topsrcdir=$TESTDIR/../../../
+export MOZBUILD_STATE_PATH=$TMP/mozbuild
+export MACH_TRY_PRESET_PATHS=$MOZBUILD_STATE_PATH/try_presets.yml
+
+# This helps to find fzf when running these tests locally, since normally fzf
+# would be found via MOZBUILD_STATE_PATH pointing to $HOME/.mozbuild
+export PATH="$PATH:$HOME/.mozbuild/fzf/bin"
+
+export MACHRC=$TMP/machrc
+cat > $MACHRC << EOF
+[try]
+default=syntax
+EOF
+
+cmd="$topsrcdir/mach python -c 'from mach.util import get_state_dir; print(get_state_dir(specific_to_topsrcdir=True))'"
+# First run local state dir generation so it doesn't affect test output.
+eval $cmd > /dev/null 2>&1
+# Now run it again to get the actual directory.
+cachedir=$(eval $cmd)/cache/taskgraph
+mkdir -p $cachedir
+
+cat > $cachedir/target_task_set << EOF
+{
+  "test/foo-opt": {
+    "kind": "test",
+    "label": "test/foo-opt",
+    "attributes": {},
+    "task": {},
+    "optimization": {},
+    "dependencies": {}
+  },
+  "test/foo-debug": {
+    "kind": "test",
+    "label": "test/foo-debug",
+    "attributes": {},
+    "task": {},
+    "optimization": {},
+    "dependencies": {}
+  },
+  "build-baz": {
+    "kind": "build",
+    "label": "build-baz",
+    "attributes": {},
+    "task": {},
+    "optimization": {},
+    "dependencies": {}
+  }
+}
+EOF
+
+cat > $cachedir/full_task_set << EOF
+{
+  "test/foo-opt": {
+    "kind": "test",
+    "label": "test/foo-opt",
+    "attributes": {},
+    "task": {},
+    "optimization": {},
+    "dependencies": {}
+  },
+  "test/foo-debug": {
+    "kind": "test",
+    "label": "test/foo-debug",
+    "attributes": {},
+    "task": {},
+    "optimization": {},
+    "dependencies": {}
+  },
+  "test/bar-opt": {
+    "kind": "test",
+    "label": "test/bar-opt",
+    "attributes": {},
+    "task": {},
+    "optimization": {},
+    "dependencies": {}
+  },
+  "test/bar-debug": {
+    "kind": "test",
+    "label": "test/bar-debug",
+    "attributes": {},
+    "task": {},
+    "optimization": {},
+    "dependencies": {}
+  },
+  "build-baz": {
+    "kind": "build",
+    "label": "build-baz",
+    "attributes": {},
+    "task": {},
+    "optimization": {},
+    "dependencies": {}
+  }
+}
+EOF
+
+# set mtime to the future so we don't re-generate tasks
+find $cachedir -type f -exec touch -d "next day" {} +
+
+export testargs="--no-push --no-artifact"
diff --git a/tools/tryselect/test/test_again.py b/tools/tryselect/test/test_again.py
new file mode 100644
index 0000000000..0e5d9d6b6d
--- /dev/null
+++ b/tools/tryselect/test/test_again.py
@@ -0,0 +1,73 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import os
+
+import mozunit
+import pytest
+from six.moves import reload_module as reload
+from tryselect import push
+from tryselect.selectors import again
+
+
+@pytest.fixture(autouse=True)
+def patch_history_path(tmpdir, monkeypatch):
+    monkeypatch.setattr(push, "history_path", tmpdir.join("history.json").strpath)
+    reload(again)
+
+
+def test_try_again(monkeypatch):
+    push.push_to_try(
+        "fuzzy",
+        "Fuzzy message",
+        try_task_config=push.generate_try_task_config(
+            "fuzzy",
+            ["foo", "bar"],
+            {"use-artifact-builds": True},
+        ),
+    )
+
+    assert os.path.isfile(push.history_path)
+    with open(push.history_path, "r") as fh:
+        assert len(fh.readlines()) == 1
+
+    def fake_push_to_try(*args, **kwargs):
+        return args, kwargs
+
+    monkeypatch.setattr(push, "push_to_try", fake_push_to_try)
+    reload(again)
+
+    args, kwargs = again.run()
+
+    assert args[0] == "again"
+    assert args[1] == "Fuzzy message"
+
+    try_task_config = kwargs.pop("try_task_config")
+    assert sorted(try_task_config.get("tasks")) == sorted(["foo", "bar"])
+    assert try_task_config.get("env") == {"TRY_SELECTOR": "fuzzy"}
+    assert try_task_config.get("use-artifact-builds")
+
+    with open(push.history_path, "r") as fh:
+        assert len(fh.readlines()) == 1
+
+
+def test_no_push_does_not_generate_history(tmpdir):
+    assert not os.path.isfile(push.history_path)
+
+    push.push_to_try(
+        "fuzzy",
+        "Fuzzy",
+        try_task_config=push.generate_try_task_config(
+            "fuzzy",
+            ["foo", "bar"],
+            {"use-artifact-builds": True},
+        ),
+        dry_run=True,
+    )
+    assert not os.path.isfile(push.history_path)
+    assert again.run() == 1
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/tools/tryselect/test/test_auto.py b/tools/tryselect/test/test_auto.py
new file mode 100644
index 0000000000..63f0fe6bd7
--- /dev/null
+++ b/tools/tryselect/test/test_auto.py
@@ -0,0 +1,31 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import mozunit
+import pytest
+from tryselect.selectors.auto import AutoParser
+
+
+def test_strategy_validation():
+    parser = AutoParser()
+    args = parser.parse_args(["--strategy", "relevant_tests"])
+    assert args.strategy == "gecko_taskgraph.optimize:tryselect.relevant_tests"
+
+    args = parser.parse_args(
+        ["--strategy", "gecko_taskgraph.optimize:experimental.relevant_tests"]
+    )
+    assert args.strategy == "gecko_taskgraph.optimize:experimental.relevant_tests"
+
+    with pytest.raises(SystemExit):
+        parser.parse_args(["--strategy", "gecko_taskgraph.optimize:tryselect"])
+
+    with pytest.raises(SystemExit):
+        parser.parse_args(["--strategy", "foo"])
+
+    with pytest.raises(SystemExit):
+        parser.parse_args(["--strategy", "foo:bar"])
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/tools/tryselect/test/test_auto.t b/tools/tryselect/test/test_auto.t
new file mode 100644
index 0000000000..c3fe797949
--- /dev/null
+++ b/tools/tryselect/test/test_auto.t
@@ -0,0 +1,61 @@
+
+  $ . $TESTDIR/setup.sh
+  $ cd $topsrcdir
+
+Test auto selector
+
+  $ ./mach try auto $testargs
+  Commit message:
+  Tasks automatically selected.
+  
+  Pushed via `mach try auto`
+  Calculated try_task_config.json:
+  {
+      "parameters": {
+          "optimize_strategies": "gecko_taskgraph.optimize:tryselect.bugbug_reduced_manifests_config_selection_medium",
+          "optimize_target_tasks": true,
+          "target_tasks_method": "try_auto",
+          "test_manifest_loader": "bugbug",
+          "try_mode": "try_auto",
+          "try_task_config": {}
+      },
+      "version": 2
+  }
+  
+
+  $ ./mach try auto $testargs --closed-tree
+  Commit message:
+  Tasks automatically selected. ON A CLOSED TREE
+  
+  Pushed via `mach try auto`
+  Calculated try_task_config.json:
+  {
+      "parameters": {
+          "optimize_strategies": "gecko_taskgraph.optimize:tryselect.bugbug_reduced_manifests_config_selection_medium",
+          "optimize_target_tasks": true,
+          "target_tasks_method": "try_auto",
+          "test_manifest_loader": "bugbug",
+          "try_mode": "try_auto",
+          "try_task_config": {}
+      },
+      "version": 2
+  }
+  
+  $ ./mach try auto $testargs --closed-tree -m "foo {msg} bar"
+  Commit message:
+  foo Tasks automatically selected. bar ON A CLOSED TREE
+  
+  Pushed via `mach try auto`
+  Calculated try_task_config.json:
+  {
+      "parameters": {
+          "optimize_strategies": "gecko_taskgraph.optimize:tryselect.bugbug_reduced_manifests_config_selection_medium",
+          "optimize_target_tasks": true,
+          "target_tasks_method": "try_auto",
+          "test_manifest_loader": "bugbug",
+          "try_mode": "try_auto",
+          "try_task_config": {}
+      },
+      "version": 2
+  }
+  
diff --git a/tools/tryselect/test/test_chooser.py b/tools/tryselect/test/test_chooser.py
new file mode 100644
index 0000000000..885ed41a78
--- /dev/null
+++ b/tools/tryselect/test/test_chooser.py
@@ -0,0 +1,77 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import mozunit
+import pytest
+from tryselect.selectors.chooser.app import create_application
+
+TASKS = [
+    {
+        "kind": "build",
+        "label": "build-windows",
+        "attributes": {
+            "build_platform": "windows",
+        },
+    },
+    {
+        "kind": "test",
+        "label": "test-windows-mochitest-e10s",
+        "attributes": {
+            "unittest_suite": "mochitest-browser-chrome",
+            "mochitest_try_name": "mochitest-browser-chrome",
+        },
+    },
+]
+
+
+@pytest.fixture
+def app(tg):
+    app = create_application(tg)
+    app.config["TESTING"] = True
+
+    ctx = app.app_context()
+    ctx.push()
+    yield app
+    ctx.pop()
+
+
+def test_try_chooser(app):
+    client = app.test_client()
+
+    response = client.get("/")
+    assert response.status_code == 200
+
+    expected_output = [
+        b"""<title>Try Chooser Enhanced</title>""",
+        b"""<input class="filter" type="checkbox" id=windows name="build" value='{"build_platform": ["windows"]}' onchange="console.log('checkbox onchange triggered');apply();">""",  # noqa
+        b"""<input class="filter" type="checkbox" id=mochitest-browser-chrome name="test" value='{"unittest_suite": ["mochitest-browser-chrome"]}' onchange="console.log('checkbox onchange triggered');apply();">""",  # noqa
+    ]
+
+    for expected in expected_output:
+        assert expected in response.data
+
+    response = client.post("/", data={"action": "Cancel"})
+    assert response.status_code == 200
+    assert b"You may now close this page" in response.data
+    assert app.tasks == []
+
+    response = client.post("/", data={"action": "Push", "selected-tasks": ""})
+    assert response.status_code == 200
+    assert b"You may now close this page" in response.data
+    assert app.tasks == []
+
+    response = client.post(
+        "/",
+        data={
+            "action": "Push",
+            "selected-tasks": "build-windows\ntest-windows-mochitest-e10s",
+        },
+    )
+    assert response.status_code == 200
+    assert b"You may now close this page" in response.data
+    assert set(app.tasks) == set(["build-windows", "test-windows-mochitest-e10s"])
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/tools/tryselect/test/test_empty.t b/tools/tryselect/test/test_empty.t
new file mode 100644
index 0000000000..f6dea366c4
--- /dev/null
+++ b/tools/tryselect/test/test_empty.t
@@ -0,0 +1,47 @@
+  $ . $TESTDIR/setup.sh
+  $ cd $topsrcdir
+
+Test empty selector
+
+  $ ./mach try empty --no-push
+  Commit message:
+  No try selector specified, use "Add New Jobs" to select tasks.
+  
+  Pushed via `mach try empty`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "TRY_SELECTOR": "empty"
+      },
+      "tasks": [],
+      "version": 1
+  }
+  
+  $ ./mach try empty --no-push --closed-tree
+  Commit message:
+  No try selector specified, use "Add New Jobs" to select tasks. ON A CLOSED TREE
+  
+  Pushed via `mach try empty`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "TRY_SELECTOR": "empty"
+      },
+      "tasks": [],
+      "version": 1
+  }
+  
+  $ ./mach try empty --no-push --closed-tree -m "foo {msg} bar"
+  Commit message:
+  foo No try selector specified, use "Add New Jobs" to select tasks. bar ON A CLOSED TREE
+  
+  Pushed via `mach try empty`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "TRY_SELECTOR": "empty"
+      },
+      "tasks": [],
+      "version": 1
+  }
+  
diff --git a/tools/tryselect/test/test_fuzzy.py b/tools/tryselect/test/test_fuzzy.py
new file mode 100644
index 0000000000..7391745beb
--- /dev/null
+++ b/tools/tryselect/test/test_fuzzy.py
@@ -0,0 +1,54 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import os
+
+import mozunit
+import pytest
+
+
+@pytest.mark.skipif(os.name == "nt", reason="fzf not installed on host")
+def test_query_paths(run_mach, capfd):
+    cmd = [
+        "try",
+        "fuzzy",
+        "--no-push",
+        "-q",
+        "^test-linux '64-qr/debug-xpcshell-nofis-",
+        "caps/tests/unit/test_origin.js",
+    ]
+    assert run_mach(cmd) == 0
+
+    output = capfd.readouterr().out
+    print(output)
+
+    # If there are more than one tasks here, it means that something went wrong
+    # with the path filtering.
+    expected = """
+    "tasks": [
+        "test-linux1804-64-qr/debug-xpcshell-nofis-1"
+    ]""".lstrip()
+
+    assert expected in output
+
+
+@pytest.mark.skipif(os.name == "nt", reason="fzf not installed on host")
+def test_query(run_mach, capfd):
+    cmd = ["try", "fuzzy", "--no-push", "-q", "'source-test-python-taskgraph-tests-py3"]
+    assert run_mach(cmd) == 0
+
+    output = capfd.readouterr().out
+    print(output)
+
+    # Should only ever mach one task exactly.
+    expected = """
+    "tasks": [
+        "source-test-python-taskgraph-tests-py3"
+    ]""".lstrip()
+
+    assert expected in output
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/tools/tryselect/test/test_fuzzy.t b/tools/tryselect/test/test_fuzzy.t
new file mode 100644
index 0000000000..d3042b0fe7
--- /dev/null
+++ b/tools/tryselect/test/test_fuzzy.t
@@ -0,0 +1,200 @@
+  $ . $TESTDIR/setup.sh
+  $ cd $topsrcdir
+
+Test fuzzy selector
+
+  $ ./mach try fuzzy $testargs -q "'foo"
+  Commit message:
+  Fuzzy query='foo
+  
+  Pushed via `mach try fuzzy`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "TRY_SELECTOR": "fuzzy"
+      },
+      "tasks": [
+          "test/foo-debug",
+          "test/foo-opt"
+      ],
+      "version": 1
+  }
+  
+  $ ./mach try fuzzy $testargs -q "'bar"
+  no tasks selected
+  $ ./mach try fuzzy $testargs --full -q "'bar"
+  Commit message:
+  Fuzzy query='bar
+  
+  Pushed via `mach try fuzzy`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "TRY_SELECTOR": "fuzzy"
+      },
+      "tasks": [
+          "test/bar-debug",
+          "test/bar-opt"
+      ],
+      "version": 1
+  }
+  
+
+Test multiple selectors
+
+  $ ./mach try fuzzy $testargs --full -q "'foo" -q "'bar"
+  Commit message:
+  Fuzzy query='foo&query='bar
+  
+  Pushed via `mach try fuzzy`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "TRY_SELECTOR": "fuzzy"
+      },
+      "tasks": [
+          "test/bar-debug",
+          "test/bar-opt",
+          "test/foo-debug",
+          "test/foo-opt"
+      ],
+      "version": 1
+  }
+  
+
+Test query intersection
+
+  $ ./mach try fuzzy $testargs --and -q "'foo" -q "'opt"
+  Commit message:
+  Fuzzy query='foo&query='opt
+  
+  Pushed via `mach try fuzzy`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "TRY_SELECTOR": "fuzzy"
+      },
+      "tasks": [
+          "test/foo-opt"
+      ],
+      "version": 1
+  }
+  
+
+Test intersection with preset containing multiple queries
+
+  $ ./mach try fuzzy --save foo -q "'test" -q "'opt"
+  preset saved, run with: --preset=foo
+
+  $ ./mach try fuzzy $testargs --preset foo -xq "'test"
+  Commit message:
+  Fuzzy query='test&query='opt&query='test
+  
+  Pushed via `mach try fuzzy`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "TRY_SELECTOR": "fuzzy"
+      },
+      "tasks": [
+          "test/foo-debug",
+          "test/foo-opt"
+      ],
+      "version": 1
+  }
+  
+  $ ./mach try $testargs --preset foo -xq "'test"
+  Commit message:
+  Fuzzy query='test&query='opt&query='test
+  
+  Pushed via `mach try fuzzy`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "TRY_SELECTOR": "fuzzy"
+      },
+      "tasks": [
+          "test/foo-debug",
+          "test/foo-opt"
+      ],
+      "version": 1
+  }
+  
+
+Test exact match
+
+  $ ./mach try fuzzy $testargs --full -q "testfoo | 'testbar"
+  Commit message:
+  Fuzzy query=testfoo | 'testbar
+  
+  Pushed via `mach try fuzzy`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "TRY_SELECTOR": "fuzzy"
+      },
+      "tasks": [
+          "test/foo-debug",
+          "test/foo-opt"
+      ],
+      "version": 1
+  }
+  
+  $ ./mach try fuzzy $testargs --full --exact -q "testfoo | 'testbar"
+  Commit message:
+  Fuzzy query=testfoo | 'testbar
+  
+  Pushed via `mach try fuzzy`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "TRY_SELECTOR": "fuzzy"
+      },
+      "tasks": [
+          "test/bar-debug",
+          "test/bar-opt"
+      ],
+      "version": 1
+  }
+  
+
+
+Test task config 
+
+  $ ./mach try fuzzy --no-push --artifact -q "'foo"
+  Commit message:
+  Fuzzy query='foo
+  
+  Pushed via `mach try fuzzy`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "TRY_SELECTOR": "fuzzy"
+      },
+      "tasks": [
+          "test/foo-debug",
+          "test/foo-opt"
+      ],
+      "use-artifact-builds": true,
+      "version": 1
+  }
+  
+  $ ./mach try fuzzy $testargs --env FOO=1 --env BAR=baz -q "'foo"
+  Commit message:
+  Fuzzy query='foo
+  
+  Pushed via `mach try fuzzy`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "BAR": "baz",
+          "FOO": "1",
+          "TRY_SELECTOR": "fuzzy"
+      },
+      "tasks": [
+          "test/foo-debug",
+          "test/foo-opt"
+      ],
+      "version": 1
+  }
+  
diff --git a/tools/tryselect/test/test_message.t b/tools/tryselect/test/test_message.t
new file mode 100644
index 0000000000..25a104833c
--- /dev/null
+++ b/tools/tryselect/test/test_message.t
@@ -0,0 +1,63 @@
+  $ . $TESTDIR/setup.sh
+  $ cd $topsrcdir
+
+Test custom commit messages with fuzzy selector
+
+  $ ./mach try fuzzy $testargs -q foo --message "Foobar"
+  Commit message:
+  Foobar
+  
+  Fuzzy query=foo
+  
+  Pushed via `mach try fuzzy`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "TRY_SELECTOR": "fuzzy"
+      },
+      "tasks": [
+          "test/foo-debug",
+          "test/foo-opt"
+      ],
+      "version": 1
+  }
+  
+  $ ./mach try fuzzy $testargs -q foo -m "Foobar: {msg}"
+  Commit message:
+  Foobar: Fuzzy query=foo
+  
+  Pushed via `mach try fuzzy`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "TRY_SELECTOR": "fuzzy"
+      },
+      "tasks": [
+          "test/foo-debug",
+          "test/foo-opt"
+      ],
+      "version": 1
+  }
+  
+  $ unset EDITOR
+  $ ./mach try fuzzy $testargs -q foo -m > /dev/null 2>&1
+  [2]
+
+
+Test custom commit messages with syntax selector
+
+  $ ./mach try syntax $testargs -p linux -u mochitests --message "Foobar"
+  Commit message:
+  Foobar
+  
+  try: -b do -p linux -u mochitests
+  
+  Pushed via `mach try syntax`
+  $ ./mach try syntax $testargs -p linux -u mochitests -m "Foobar: {msg}"
+  Commit message:
+  Foobar: try: -b do -p linux -u mochitests
+  
+  Pushed via `mach try syntax`
+  $ unset EDITOR
+  $ ./mach try syntax $testargs -p linux -u mochitests -m > /dev/null 2>&1
+  [2]
diff --git a/tools/tryselect/test/test_mozharness_integration.py b/tools/tryselect/test/test_mozharness_integration.py
new file mode 100644
index 0000000000..984f8de25b
--- /dev/null
+++ b/tools/tryselect/test/test_mozharness_integration.py
@@ -0,0 +1,143 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import imp
+import json
+import os
+
+import mozunit
+import pytest
+from tryselect.tasks import build, resolve_tests_by_suite
+
+MOZHARNESS_SCRIPTS = {
+    "android_emulator_unittest": {
+        "class_name": "AndroidEmulatorTest",
+        "configs": [
+            "android/android_common.py",
+        ],
+        "xfail": [
+            "cppunittest",
+            "crashtest-qr",
+            "gtest",
+            "geckoview-junit",
+            "jittest",
+            "jsreftest",
+            "reftest-qr",
+        ],
+    },
+    "desktop_unittest": {
+        "class_name": "DesktopUnittest",
+        "configs": [
+            "unittests/linux_unittest.py",
+            "unittests/mac_unittest.py",
+            "unittests/win_unittest.py",
+        ],
+        "xfail": [
+            "cppunittest",
+            "gtest",
+            "jittest",
+            "jittest-chunked",
+            "jittest1",
+            "jittest2",
+            "jsreftest",
+            "mochitest-valgrind-plain",
+            "reftest-no-accel",
+            "reftest-snapshot",
+            "xpcshell-msix",
+        ],
+    },
+}
+"""A suite being listed in a script's `xfail` list  means it won't work
+properly with MOZHARNESS_TEST_PATHS (the mechanism |mach try fuzzy <path>|
+uses).
+"""
+
+
+def get_mozharness_test_paths(name):
+    scriptdir = os.path.join(build.topsrcdir, "testing", "mozharness", "scripts")
+
+    files = imp.find_module(name, [scriptdir])
+    mod = imp.load_module("scripts.{}".format(name), *files)
+
+    class_name = MOZHARNESS_SCRIPTS[name]["class_name"]
+    cls = getattr(mod, class_name)
+    return cls(require_config_file=False)._get_mozharness_test_paths
+
+
+@pytest.fixture(scope="module")
+def all_suites():
+    from moztest.resolve import _test_flavors, _test_subsuites
+
+    all_suites = []
+    for flavor in _test_flavors:
+        all_suites.append({"flavor": flavor, "srcdir_relpath": "test"})
+
+    for flavor, subsuite in _test_subsuites:
+        all_suites.append(
+            {"flavor": flavor, "subsuite": subsuite, "srcdir_relpath": "test"}
+        )
+
+    return all_suites
+
+
+def generate_suites_from_config(path):
+    configdir = os.path.join(build.topsrcdir, "testing", "mozharness", "configs")
+
+    parent, name = os.path.split(path)
+    name = os.path.splitext(name)[0]
+
+    files = imp.find_module("{}".format(name), [os.path.join(configdir, parent)])
+    mod = imp.load_module("config.{}".format(name), *files)
+    config = mod.config
+
+    for category in sorted(config["suite_definitions"]):
+        key = "all_{}_suites".format(category)
+        if key not in config:
+            yield category,
+            continue
+
+        for suite in sorted(config["all_{}_suites".format(category)]):
+            yield category, suite
+
+
+def generate_suites():
+    for name, script in MOZHARNESS_SCRIPTS.items():
+        seen = set()
+
+        for path in script["configs"]:
+            for suite in generate_suites_from_config(path):
+                if suite in seen:
+                    continue
+                seen.add(suite)
+
+                item = (name, suite)
+
+                if suite[-1] in script["xfail"]:
+                    item = pytest.param(item, marks=pytest.mark.xfail)
+
+                yield item
+
+
+def idfn(item):
+    name, suite = item
+    return "{}/{}".format(name, suite[-1])
+
+
+@pytest.mark.parametrize("item", generate_suites(), ids=idfn)
+def test_suites(item, patch_resolver, all_suites):
+    """An integration test to make sure the suites returned by
+    `tasks.resolve_tests_by_suite` match up with the names defined in
+    mozharness.
+    """
+    patch_resolver([], all_suites)
+    suites = resolve_tests_by_suite(["test"])
+    os.environ["MOZHARNESS_TEST_PATHS"] = json.dumps(suites)
+
+    name, suite = item
+    func = get_mozharness_test_paths(name)
+    assert func(*suite)
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/tools/tryselect/test/test_perf.py b/tools/tryselect/test/test_perf.py
new file mode 100644
index 0000000000..b3ad5d9575
--- /dev/null
+++ b/tools/tryselect/test/test_perf.py
@@ -0,0 +1,854 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import os
+from unittest import mock
+
+import mozunit
+import pytest
+from tryselect.selectors.perf import (
+    Apps,
+    InvalidCategoryException,
+    PerfParser,
+    Platforms,
+    Suites,
+    Variants,
+    check_for_live_sites,
+    check_for_profile,
+    run,
+)
+
+TASKS = [
+    "test-linux1804-64-shippable-qr/opt-browsertime-benchmark-firefox-motionmark-animometer",
+    "test-linux1804-64-shippable-qr/opt-browsertime-benchmark-wasm-firefox-wasm-godot-optimizing",
+    "test-linux1804-64-shippable-qr/opt-browsertime-benchmark-firefox-webaudio",
+    "test-linux1804-64-shippable-qr/opt-browsertime-benchmark-firefox-speedometer",
+    "test-linux1804-64-shippable-qr/opt-browsertime-benchmark-wasm-firefox-wasm-misc",
+    "test-linux1804-64-shippable-qr/opt-browsertime-benchmark-firefox-jetstream2",
+    "test-linux1804-64-shippable-qr/opt-browsertime-benchmark-firefox-ares6",
+    "test-linux1804-64-shippable-qr/opt-browsertime-benchmark-wasm-firefox-wasm-misc-optimizing",
+    "test-linux1804-64-shippable-qr/opt-browsertime-benchmark-firefox-sunspider",
+    "test-linux1804-64-shippable-qr/opt-browsertime-benchmark-firefox-matrix-react-bench",
+    "test-linux1804-64-shippable-qr/opt-browsertime-benchmark-wasm-firefox-wasm-godot-baseline",
+    "test-linux1804-64-shippable-qr/opt-browsertime-benchmark-firefox-twitch-animation",
+    "test-linux1804-64-shippable-qr/opt-browsertime-benchmark-firefox-assorted-dom",
+    "test-linux1804-64-shippable-qr/opt-browsertime-benchmark-firefox-stylebench",
+    "test-linux1804-64-shippable-qr/opt-browsertime-benchmark-wasm-firefox-wasm-misc-baseline",
+    "test-linux1804-64-shippable-qr/opt-browsertime-benchmark-firefox-motionmark-htmlsuite",
+    "test-linux1804-64-shippable-qr/opt-browsertime-benchmark-firefox-unity-webgl",
+    "test-linux1804-64-shippable-qr/opt-browsertime-benchmark-wasm-firefox-wasm-godot",
+]
+
+# The TEST_VARIANTS, and TEST_CATEGORIES are used to force
+# a particular set of categories to show up in testing. Otherwise,
+# every time someone adds a category, or a variant, we'll need
+# to redo all the category counts. The platforms, and apps are
+# not forced because they change infrequently.
+TEST_VARIANTS = {
+    Variants.NO_FISSION.value: {
+        "query": "'nofis",
+        "negation": "!nofis",
+        "platforms": [Platforms.ANDROID.value],
+        "apps": [Apps.FENIX.value, Apps.GECKOVIEW.value],
+    },
+    Variants.BYTECODE_CACHED.value: {
+        "query": "'bytecode",
+        "negation": "!bytecode",
+        "platforms": [Platforms.DESKTOP.value],
+        "apps": [Apps.FIREFOX.value],
+    },
+    Variants.LIVE_SITES.value: {
+        "query": "'live",
+        "negation": "!live",
+        "restriction": check_for_live_sites,
+        "platforms": [Platforms.DESKTOP.value, Platforms.ANDROID.value],
+        "apps": list(PerfParser.apps.keys()),
+    },
+    Variants.PROFILING.value: {
+        "query": "'profil",
+        "negation": "!profil",
+        "restriction": check_for_profile,
+        "platforms": [Platforms.DESKTOP.value, Platforms.ANDROID.value],
+        "apps": [Apps.FIREFOX.value, Apps.GECKOVIEW.value, Apps.FENIX.value],
+    },
+    Variants.SWR.value: {
+        "query": "'swr",
+        "negation": "!swr",
+        "platforms": [Platforms.DESKTOP.value],
+        "apps": [Apps.FIREFOX.value],
+    },
+}
+
+TEST_CATEGORIES = {
+    "Pageload": {
+        "query": {
+            Suites.RAPTOR.value: ["'browsertime 'tp6"],
+        },
+        "suites": [Suites.RAPTOR.value],
+        "tasks": [],
+    },
+    "Pageload (essential)": {
+        "query": {
+            Suites.RAPTOR.value: ["'browsertime 'tp6 'essential"],
+        },
+        "variant-restrictions": {Suites.RAPTOR.value: [Variants.NO_FISSION.value]},
+        "suites": [Suites.RAPTOR.value],
+        "tasks": [],
+    },
+    "Responsiveness": {
+        "query": {
+            Suites.RAPTOR.value: ["'browsertime 'responsive"],
+        },
+        "suites": [Suites.RAPTOR.value],
+        "variant-restrictions": {Suites.RAPTOR.value: []},
+        "tasks": [],
+    },
+    "Benchmarks": {
+        "query": {
+            Suites.RAPTOR.value: ["'browsertime 'benchmark"],
+        },
+        "suites": [Suites.RAPTOR.value],
+        "variant-restrictions": {Suites.RAPTOR.value: []},
+        "tasks": [],
+    },
+    "DAMP (Devtools)": {
+        "query": {
+            Suites.TALOS.value: ["'talos 'damp"],
+        },
+        "suites": [Suites.TALOS.value],
+        "tasks": [],
+    },
+    "Talos PerfTests": {
+        "query": {
+            Suites.TALOS.value: ["'talos"],
+        },
+        "suites": [Suites.TALOS.value],
+        "tasks": [],
+    },
+    "Resource Usage": {
+        "query": {
+            Suites.TALOS.value: ["'talos 'xperf | 'tp5"],
+            Suites.RAPTOR.value: ["'power 'osx"],
+            Suites.AWSY.value: ["'awsy"],
+        },
+        "suites": [Suites.TALOS.value, Suites.RAPTOR.value, Suites.AWSY.value],
+        "platform-restrictions": [Platforms.DESKTOP.value],
+        "variant-restrictions": {
+            Suites.RAPTOR.value: [],
+            Suites.TALOS.value: [],
+        },
+        "app-restrictions": {
+            Suites.RAPTOR.value: [Apps.FIREFOX.value],
+            Suites.TALOS.value: [Apps.FIREFOX.value],
+        },
+        "tasks": [],
+    },
+    "Graphics, & Media Playback": {
+        "query": {
+            # XXX This might not be an exhaustive list for talos atm
+            Suites.TALOS.value: ["'talos 'svgr | 'bcv | 'webgl"],
+            Suites.RAPTOR.value: ["'browsertime 'youtube-playback"],
+        },
+        "suites": [Suites.TALOS.value, Suites.RAPTOR.value],
+        "variant-restrictions": {Suites.RAPTOR.value: [Variants.NO_FISSION.value]},
+        "tasks": [],
+    },
+}
+
+
+@pytest.mark.parametrize(
+    "category_options, expected_counts, unique_categories, missing",
+    [
+        # Default should show the premade live category, but no chrome or android
+        # The benchmark desktop category should be visible in all configurations
+        # except for when there are requested apps/variants/platforms
+        (
+            {},
+            58,
+            {
+                "Benchmarks desktop": {
+                    "raptor": [
+                        "'browsertime 'benchmark",
+                        "!android 'shippable !-32 !clang",
+                        "!bytecode",
+                        "!live",
+                        "!profil",
+                        "!chrom",
+                        "!safari",
+                    ]
+                },
+                "Pageload macosx": {
+                    "raptor": [
+                        "'browsertime 'tp6",
+                        "'osx 'shippable",
+                        "!bytecode",
+                        "!live",
+                        "!profil",
+                        "!chrom",
+                        "!safari",
+                    ]
+                },
+                "Resource Usage desktop": {
+                    "awsy": ["'awsy", "!android 'shippable !-32 !clang"],
+                    "raptor": [
+                        "'power 'osx",
+                        "!android 'shippable !-32 !clang",
+                        "!bytecode",
+                        "!live",
+                        "!profil",
+                        "!chrom",
+                        "!safari",
+                    ],
+                    "talos": [
+                        "'talos 'xperf | 'tp5",
+                        "!android 'shippable !-32 !clang",
+                        "!profil",
+                        "!swr",
+                    ],
+                },
+            },
+            [
+                "Responsiveness android-p2 geckoview",
+                "Benchmarks desktop chromium",
+            ],
+        ),  # Default settings
+        (
+            {"live_sites": True},
+            66,
+            {
+                "Benchmarks desktop": {
+                    "raptor": [
+                        "'browsertime 'benchmark",
+                        "!android 'shippable !-32 !clang",
+                        "!bytecode",
+                        "!profil",
+                        "!chrom",
+                        "!safari",
+                    ]
+                },
+                "Pageload macosx": {
+                    "raptor": [
+                        "'browsertime 'tp6",
+                        "'osx 'shippable",
+                        "!bytecode",
+                        "!profil",
+                        "!chrom",
+                        "!safari",
+                    ]
+                },
+                "Pageload macosx live-sites": {
+                    "raptor": [
+                        "'browsertime 'tp6",
+                        "'osx 'shippable",
+                        "'live",
+                        "!bytecode",
+                        "!profil",
+                        "!chrom",
+                        "!safari",
+                    ],
+                },
+            },
+            [
+                "Responsiveness android-p2 geckoview",
+                "Benchmarks desktop chromium",
+                "Benchmarks desktop firefox profiling",
+                "Talos desktop live-sites",
+                "Talos desktop profiling+swr",
+                "Benchmarks desktop firefox live-sites+profiling"
+                "Benchmarks desktop firefox live-sites",
+            ],
+        ),
+        (
+            {"live_sites": True, "safari": True},
+            72,
+            {
+                "Benchmarks desktop": {
+                    "raptor": [
+                        "'browsertime 'benchmark",
+                        "!android 'shippable !-32 !clang",
+                        "!bytecode",
+                        "!profil",
+                        "!chrom",
+                    ]
+                },
+                "Pageload macosx safari": {
+                    "raptor": [
+                        "'browsertime 'tp6",
+                        "'osx 'shippable",
+                        "'safari",
+                        "!bytecode",
+                        "!profil",
+                    ]
+                },
+                "Pageload macosx safari live-sites": {
+                    "raptor": [
+                        "'browsertime 'tp6",
+                        "'osx 'shippable",
+                        "'safari",
+                        "'live",
+                        "!bytecode",
+                        "!profil",
+                    ],
+                },
+            },
+            [
+                "Pageload linux safari",
+                "Pageload desktop safari",
+            ],
+        ),
+        (
+            {"live_sites": True, "chrome": True},
+            114,
+            {
+                "Benchmarks desktop": {
+                    "raptor": [
+                        "'browsertime 'benchmark",
+                        "!android 'shippable !-32 !clang",
+                        "!bytecode",
+                        "!profil",
+                        "!safari",
+                    ]
+                },
+                "Pageload macosx live-sites": {
+                    "raptor": [
+                        "'browsertime 'tp6",
+                        "'osx 'shippable",
+                        "'live",
+                        "!bytecode",
+                        "!profil",
+                        "!safari",
+                    ],
+                },
+                "Benchmarks desktop chromium": {
+                    "raptor": [
+                        "'browsertime 'benchmark",
+                        "!android 'shippable !-32 !clang",
+                        "'chromium",
+                        "!bytecode",
+                        "!profil",
+                    ],
+                },
+            },
+            [
+                "Responsiveness android-p2 geckoview",
+                "Firefox Pageload linux chrome",
+                "Talos PerfTests desktop swr",
+            ],
+        ),
+        (
+            {"android": True},
+            88,
+            {
+                "Benchmarks desktop": {
+                    "raptor": [
+                        "'browsertime 'benchmark",
+                        "!android 'shippable !-32 !clang",
+                        "!bytecode",
+                        "!live",
+                        "!profil",
+                        "!chrom",
+                        "!safari",
+                    ],
+                },
+                "Responsiveness android-a51 geckoview": {
+                    "raptor": [
+                        "'browsertime 'responsive",
+                        "'android 'a51 'shippable 'aarch64",
+                        "'geckoview",
+                        "!nofis",
+                        "!live",
+                        "!profil",
+                    ],
+                },
+            },
+            [
+                "Responsiveness android-a51 chrome-m",
+                "Firefox Pageload android",
+            ],
+        ),
+        (
+            {"android": True, "chrome": True},
+            138,
+            {
+                "Benchmarks desktop": {
+                    "raptor": [
+                        "'browsertime 'benchmark",
+                        "!android 'shippable !-32 !clang",
+                        "!bytecode",
+                        "!live",
+                        "!profil",
+                        "!safari",
+                    ],
+                },
+                "Responsiveness android-a51 chrome-m": {
+                    "raptor": [
+                        "'browsertime 'responsive",
+                        "'android 'a51 'shippable 'aarch64",
+                        "'chrome-m",
+                        "!nofis",
+                        "!live",
+                        "!profil",
+                    ],
+                },
+            },
+            ["Responsiveness android-p2 chrome-m", "Resource Usage android"],
+        ),
+        (
+            {"android": True, "chrome": True, "profile": True},
+            176,
+            {
+                "Benchmarks desktop": {
+                    "raptor": [
+                        "'browsertime 'benchmark",
+                        "!android 'shippable !-32 !clang",
+                        "!bytecode",
+                        "!live",
+                        "!safari",
+                    ]
+                },
+                "Talos PerfTests desktop profiling": {
+                    "talos": [
+                        "'talos",
+                        "!android 'shippable !-32 !clang",
+                        "'profil",
+                        "!swr",
+                    ]
+                },
+            },
+            [
+                "Resource Usage desktop profiling",
+                "DAMP (Devtools) desktop chrome",
+                "Resource Usage android",
+                "Resource Usage windows chromium",
+            ],
+        ),
+        # Show all available windows tests, no other platform should exist
+        # including the desktop catgeory
+        (
+            {"requested_platforms": ["windows"]},
+            14,
+            {
+                "Benchmarks windows firefox": {
+                    "raptor": [
+                        "'browsertime 'benchmark",
+                        "!-32 'windows 'shippable",
+                        "!chrom !geckoview !fenix !safari",
+                        "!bytecode",
+                        "!live",
+                        "!profil",
+                    ]
+                },
+            },
+            [
+                "Resource Usage desktop",
+                "Benchmarks desktop",
+                "Benchmarks linux firefox bytecode-cached+profiling",
+            ],
+        ),
+        # Can't have fenix on the windows platform
+        (
+            {"requested_platforms": ["windows"], "requested_apps": ["fenix"]},
+            0,
+            {},
+            ["Benchmarks desktop"],
+        ),
+        # Android flag also needs to be supplied
+        (
+            {"requested_platforms": ["android"], "requested_apps": ["fenix"]},
+            0,
+            {},
+            ["Benchmarks desktop"],
+        ),
+        # There should be no global categories available, only fenix
+        (
+            {
+                "requested_platforms": ["android"],
+                "requested_apps": ["fenix"],
+                "android": True,
+            },
+            10,
+            {
+                "Pageload android fenix": {
+                    "raptor": [
+                        "'browsertime 'tp6",
+                        "'android 'a51 'shippable 'aarch64",
+                        "'fenix",
+                        "!nofis",
+                        "!live",
+                        "!profil",
+                    ],
+                }
+            },
+            ["Benchmarks desktop", "Pageload (live) android"],
+        ),
+        # Test with multiple apps
+        (
+            {
+                "requested_platforms": ["android"],
+                "requested_apps": ["fenix", "geckoview"],
+                "android": True,
+            },
+            15,
+            {
+                "Benchmarks android geckoview": {
+                    "raptor": [
+                        "'browsertime 'benchmark",
+                        "'android 'a51 'shippable 'aarch64",
+                        "'geckoview",
+                        "!nofis",
+                        "!live",
+                        "!profil",
+                    ],
+                },
+                "Pageload android fenix": {
+                    "raptor": [
+                        "'browsertime 'tp6",
+                        "'android 'a51 'shippable 'aarch64",
+                        "'fenix",
+                        "!nofis",
+                        "!live",
+                        "!profil",
+                    ],
+                },
+            },
+            [
+                "Benchmarks desktop",
+                "Pageload android no-fission",
+                "Pageload android fenix live-sites",
+            ],
+        ),
+        # Variants are inclusive, so we'll see the variant alongside the
+        # base here for fenix
+        (
+            {
+                "requested_variants": ["no-fission"],
+                "requested_apps": ["fenix"],
+                "android": True,
+            },
+            32,
+            {
+                "Pageload android-a51 fenix": {
+                    "raptor": [
+                        "'browsertime 'tp6",
+                        "'android 'a51 'shippable 'aarch64",
+                        "'fenix",
+                        "!live",
+                        "!profil",
+                    ],
+                },
+                "Pageload android-a51 fenix no-fission": {
+                    "raptor": [
+                        "'browsertime 'tp6",
+                        "'android 'a51 'shippable 'aarch64",
+                        "'fenix",
+                        "'nofis",
+                        "!live",
+                        "!profil",
+                    ],
+                },
+                "Pageload (essential) android fenix no-fission": {
+                    "raptor": [
+                        "'browsertime 'tp6 'essential",
+                        "'android 'a51 'shippable 'aarch64",
+                        "'fenix",
+                        "'nofis",
+                        "!live",
+                        "!profil",
+                    ],
+                },
+            },
+            [
+                "Benchmarks desktop",
+                "Pageload (live) android",
+                "Pageload android-p2 fenix live-sites",
+            ],
+        ),
+        # With multiple variants, we'll see the base variant (with no combinations)
+        # for each of them
+        (
+            {
+                "requested_variants": ["no-fission", "live-sites"],
+                "requested_apps": ["fenix"],
+                "android": True,
+            },
+            40,
+            {
+                "Pageload android-a51 fenix": {
+                    "raptor": [
+                        "'browsertime 'tp6",
+                        "'android 'a51 'shippable 'aarch64",
+                        "'fenix",
+                        "!profil",
+                    ],
+                },
+                "Pageload android-a51 fenix no-fission": {
+                    "raptor": [
+                        "'browsertime 'tp6",
+                        "'android 'a51 'shippable 'aarch64",
+                        "'fenix",
+                        "'nofis",
+                        "!live",
+                        "!profil",
+                    ],
+                },
+                "Pageload android-a51 fenix live-sites": {
+                    "raptor": [
+                        "'browsertime 'tp6",
+                        "'android 'a51 'shippable 'aarch64",
+                        "'fenix",
+                        "'live",
+                        "!nofis",
+                        "!profil",
+                    ],
+                },
+                "Pageload (essential) android fenix no-fission": {
+                    "raptor": [
+                        "'browsertime 'tp6 'essential",
+                        "'android 'a51 'shippable 'aarch64",
+                        "'fenix",
+                        "'nofis",
+                        "!live",
+                        "!profil",
+                    ],
+                },
+                "Pageload android fenix no-fission+live-sites": {
+                    "raptor": [
+                        "'browsertime 'tp6",
+                        "'android 'a51 'shippable 'aarch64",
+                        "'fenix",
+                        "'nofis",
+                        "'live",
+                        "!profil",
+                    ],
+                },
+            },
+            [
+                "Benchmarks desktop",
+                "Pageload (live) android",
+                "Pageload android-p2 fenix live-sites",
+                "Pageload (essential) android fenix no-fission+live-sites",
+            ],
+        ),
+        # Make sure that no no-fission tasks are selected when a variant cannot
+        # run on a requested platform
+        (
+            {
+                "requested_variants": ["no-fission"],
+                "requested_platforms": ["windows"],
+            },
+            14,
+            {
+                "Responsiveness windows firefox": {
+                    "raptor": [
+                        "'browsertime 'responsive",
+                        "!-32 'windows 'shippable",
+                        "!chrom !geckoview !fenix !safari",
+                        "!bytecode",
+                        "!live",
+                        "!profil",
+                    ],
+                },
+            },
+            ["Benchmarks desktop", "Responsiveness windows firefox no-fisson"],
+        ),
+        # We should only see the base and the live-site variants here for windows
+        (
+            {
+                "requested_variants": ["no-fission", "live-sites"],
+                "requested_platforms": ["windows"],
+                "android": True,
+            },
+            16,
+            {
+                "Responsiveness windows firefox": {
+                    "raptor": [
+                        "'browsertime 'responsive",
+                        "!-32 'windows 'shippable",
+                        "!chrom !geckoview !fenix !safari",
+                        "!bytecode",
+                        "!profil",
+                    ],
+                },
+                "Pageload windows live-sites": {
+                    "raptor": [
+                        "'browsertime 'tp6",
+                        "!-32 'windows 'shippable",
+                        "'live",
+                        "!bytecode",
+                        "!profil",
+                        "!chrom",
+                        "!safari",
+                    ],
+                },
+                "Graphics, & Media Playback windows": {
+                    "raptor": [
+                        "'browsertime 'youtube-playback",
+                        "!-32 'windows 'shippable",
+                        "!bytecode",
+                        "!profil",
+                        "!chrom",
+                        "!safari",
+                    ],
+                    "talos": [
+                        "'talos 'svgr | 'bcv | 'webgl",
+                        "!-32 'windows 'shippable",
+                        "!profil",
+                        "!swr",
+                    ],
+                },
+            },
+            [
+                "Benchmarks desktop",
+                "Responsiveness windows firefox no-fisson",
+                "Pageload (live) android",
+                "Talos desktop live-sites",
+                "Talos android",
+                "Graphics, & Media Playback windows live-sites",
+                "Graphics, & Media Playback android no-fission",
+            ],
+        ),
+    ],
+)
+def test_category_expansion(
+    category_options, expected_counts, unique_categories, missing
+):
+    # Set the categories, and variants to expand
+    PerfParser.categories = TEST_CATEGORIES
+    PerfParser.variants = TEST_VARIANTS
+
+    # Expand the categories, then either check if the unique_categories,
+    # exist or are missing from the categories
+    expanded_cats = PerfParser.get_categories(**category_options)
+
+    assert len(expanded_cats) == expected_counts
+    assert not any([expanded_cats.get(ucat, None) is not None for ucat in missing])
+    assert all(
+        [expanded_cats.get(ucat, None) is not None for ucat in unique_categories.keys()]
+    )
+
+    # Ensure that the queries are as expected
+    for cat_name, cat_query in unique_categories.items():
+        # Don't use get here because these fields should always exist
+        assert cat_query == expanded_cats[cat_name]["queries"]
+
+
+@pytest.mark.parametrize(
+    "options, call_counts, log_ind, expected_log_message",
+    [
+        (
+            {},
+            [8, 2, 2, 5],
+            2,
+            (
+                "\n!!!NOTE!!!\n You'll be able to find a performance comparison "
+                "here once the tests are complete (ensure you select the right framework): "
+                "https://treeherder.mozilla.org/perfherder/compare?originalProject=try&original"
+                "Revision=revision&newProject=try&newRevision=revision\n"
+            ),
+        ),
+        (
+            {"dry_run": True},
+            [8, 1, 1, 5],
+            2,
+            (
+                "\n!!!NOTE!!!\n You'll be able to find a performance comparison "
+                "here once the tests are complete (ensure you select the right framework): "
+                "https://treeherder.mozilla.org/perfherder/compare?originalProject=try&original"
+                "Revision=&newProject=try&newRevision=revision\n"
+            ),
+        ),
+        (
+            {"show_all": True},
+            [1, 2, 2, 3],
+            0,
+            (
+                "\n!!!NOTE!!!\n You'll be able to find a performance comparison "
+                "here once the tests are complete (ensure you select the right framework): "
+                "https://treeherder.mozilla.org/perfherder/compare?originalProject=try&original"
+                "Revision=revision&newProject=try&newRevision=revision\n"
+            ),
+        ),
+        (
+            {"single_run": True},
+            [8, 1, 1, 4],
+            2,
+            (
+                "If you need any help, you can find us in the #perf-help Matrix channel:\n"
+                "https://matrix.to/#/#perf-help:mozilla.org\n"
+            ),
+        ),
+    ],
+)
+@pytest.mark.skipif(os.name == "nt", reason="fzf not installed on host")
+def test_full_run(options, call_counts, log_ind, expected_log_message):
+    with mock.patch("tryselect.selectors.perf.push_to_try") as ptt, mock.patch(
+        "tryselect.selectors.perf.run_fzf"
+    ) as fzf, mock.patch(
+        "tryselect.selectors.perf.get_repository_object", new=mock.MagicMock()
+    ), mock.patch(
+        "tryselect.selectors.perf.LogProcessor.revision",
+        new_callable=mock.PropertyMock,
+        return_value="revision",
+    ) as logger, mock.patch(
+        "tryselect.selectors.perf.print",
+    ) as perf_print:
+        fzf.side_effect = [
+            ["", ["Benchmarks linux"]],
+            ["", TASKS],
+            ["", TASKS],
+            ["", TASKS],
+            ["", TASKS],
+            ["", TASKS],
+            ["", TASKS],
+            ["", TASKS],
+        ]
+
+        run(**options)
+
+        assert fzf.call_count == call_counts[0]
+        assert ptt.call_count == call_counts[1]
+        assert logger.call_count == call_counts[2]
+        assert perf_print.call_count == call_counts[3]
+        assert perf_print.call_args_list[log_ind][0][0] == expected_log_message
+
+
+@pytest.mark.parametrize(
+    "query, should_fail",
+    [
+        (
+            {
+                "query": {
+                    # Raptor has all variants available so it
+                    # should fail on this category
+                    "raptor": ["browsertime 'live 'no-fission"],
+                }
+            },
+            True,
+        ),
+        (
+            {
+                "query": {
+                    # Awsy has no variants defined so it shouldn't fail
+                    # on a query like this
+                    "awsy": ["browsertime 'live 'no-fission"],
+                }
+            },
+            False,
+        ),
+    ],
+)
+def test_category_rules(query, should_fail):
+    # Set the categories, and variants to expand
+    PerfParser.categories = {"test-live": query}
+    PerfParser.variants = TEST_VARIANTS
+
+    if should_fail:
+        with pytest.raises(InvalidCategoryException):
+            PerfParser.run_category_checks()
+    else:
+        assert PerfParser.run_category_checks()
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/tools/tryselect/test/test_preset.t b/tools/tryselect/test/test_preset.t
new file mode 100644
index 0000000000..7fa76e17bb
--- /dev/null
+++ b/tools/tryselect/test/test_preset.t
@@ -0,0 +1,360 @@
+  $ . $TESTDIR/setup.sh
+  $ cd $topsrcdir
+
+Test preset with no subcommand
+
+  $ ./mach try $testargs --save foo -b do -p linux -u mochitests -t none --tag foo
+  preset saved, run with: --preset=foo
+
+  $ ./mach try $testargs --preset foo
+  Commit message:
+  try: -b do -p linux -u mochitests -t none --tag foo
+  
+  Pushed via `mach try syntax`
+
+  $ ./mach try syntax $testargs --preset foo
+  Commit message:
+  try: -b do -p linux -u mochitests -t none --tag foo
+  
+  Pushed via `mach try syntax`
+
+  $ ./mach try $testargs --list-presets
+  Presets from */mozbuild/try_presets.yml: (glob)
+  
+    foo:
+      no_artifact: true
+      platforms:
+      - linux
+      selector: syntax
+      tags:
+      - foo
+      talos:
+      - none
+      tests:
+      - mochitests
+    
+  $ unset EDITOR
+  $ ./mach try $testargs --edit-presets
+  error: must set the $EDITOR environment variable to use --edit-presets
+  $ export EDITOR=cat
+  $ ./mach try $testargs --edit-presets
+  foo:
+    no_artifact: true
+    platforms:
+    - linux
+    selector: syntax
+    tags:
+    - foo
+    talos:
+    - none
+    tests:
+    - mochitests
+
+Test preset with syntax subcommand
+
+  $ ./mach try syntax $testargs --save bar -b do -p win32 -u none -t all --tag bar
+  preset saved, run with: --preset=bar
+
+  $ ./mach try syntax $testargs --preset bar
+  Commit message:
+  try: -b do -p win32 -u none -t all --tag bar
+  
+  Pushed via `mach try syntax`
+
+  $ ./mach try $testargs --preset bar
+  Commit message:
+  try: -b do -p win32 -u none -t all --tag bar
+  
+  Pushed via `mach try syntax`
+
+  $ ./mach try syntax $testargs --list-presets
+  Presets from */mozbuild/try_presets.yml: (glob)
+  
+    bar:
+      dry_run: true
+      no_artifact: true
+      platforms:
+      - win32
+      selector: syntax
+      tags:
+      - bar
+      talos:
+      - all
+      tests:
+      - none
+    foo:
+      no_artifact: true
+      platforms:
+      - linux
+      selector: syntax
+      tags:
+      - foo
+      talos:
+      - none
+      tests:
+      - mochitests
+    
+  $ ./mach try syntax $testargs --edit-presets
+  bar:
+    dry_run: true
+    no_artifact: true
+    platforms:
+    - win32
+    selector: syntax
+    tags:
+    - bar
+    talos:
+    - all
+    tests:
+    - none
+  foo:
+    no_artifact: true
+    platforms:
+    - linux
+    selector: syntax
+    tags:
+    - foo
+    talos:
+    - none
+    tests:
+    - mochitests
+
+Test preset with fuzzy subcommand
+
+  $ ./mach try fuzzy $testargs --save baz -q "'foo" --rebuild 5
+  preset saved, run with: --preset=baz
+
+  $ ./mach try fuzzy $testargs --preset baz
+  Commit message:
+  Fuzzy query='foo
+  
+  Pushed via `mach try fuzzy`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "TRY_SELECTOR": "fuzzy"
+      },
+      "rebuild": 5,
+      "tasks": [
+          "test/foo-debug",
+          "test/foo-opt"
+      ],
+      "version": 1
+  }
+  
+
+  $ ./mach try $testargs --preset baz
+  Commit message:
+  Fuzzy query='foo
+  
+  Pushed via `mach try fuzzy`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "TRY_SELECTOR": "fuzzy"
+      },
+      "rebuild": 5,
+      "tasks": [
+          "test/foo-debug",
+          "test/foo-opt"
+      ],
+      "version": 1
+  }
+  
+ 
+Queries can be appended to presets
+
+  $ ./mach try fuzzy $testargs --preset baz -q "'build"
+  Commit message:
+  Fuzzy query='foo&query='build
+  
+  Pushed via `mach try fuzzy`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "TRY_SELECTOR": "fuzzy"
+      },
+      "rebuild": 5,
+      "tasks": [
+          "build-baz",
+          "test/foo-debug",
+          "test/foo-opt"
+      ],
+      "version": 1
+  }
+  
+
+  $ ./mach try $testargs --preset baz -xq "'opt"
+  Commit message:
+  Fuzzy query='foo&query='opt
+  
+  Pushed via `mach try fuzzy`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "TRY_SELECTOR": "fuzzy"
+      },
+      "rebuild": 5,
+      "tasks": [
+          "test/foo-opt"
+      ],
+      "version": 1
+  }
+  
+
+  $ ./mach try fuzzy $testargs --list-presets
+  Presets from */mozbuild/try_presets.yml: (glob)
+  
+    bar:
+      dry_run: true
+      no_artifact: true
+      platforms:
+      - win32
+      selector: syntax
+      tags:
+      - bar
+      talos:
+      - all
+      tests:
+      - none
+    baz:
+      dry_run: true
+      no_artifact: true
+      query:
+      - '''foo'
+      rebuild: 5
+      selector: fuzzy
+    foo:
+      no_artifact: true
+      platforms:
+      - linux
+      selector: syntax
+      tags:
+      - foo
+      talos:
+      - none
+      tests:
+      - mochitests
+    
+  $ ./mach try fuzzy $testargs --edit-presets
+  bar:
+    dry_run: true
+    no_artifact: true
+    platforms:
+    - win32
+    selector: syntax
+    tags:
+    - bar
+    talos:
+    - all
+    tests:
+    - none
+  baz:
+    dry_run: true
+    no_artifact: true
+    query:
+    - '''foo'
+    rebuild: 5
+    selector: fuzzy
+  foo:
+    no_artifact: true
+    platforms:
+    - linux
+    selector: syntax
+    tags:
+    - foo
+    talos:
+    - none
+    tests:
+    - mochitests
+
+Test gecko-profile argument handling. Add in profiling to a preset.
+
+  $ ./mach try fuzzy $testargs --preset baz --gecko-profile-features=nostacksampling,cpu
+  Commit message:
+  Fuzzy query='foo
+  
+  Pushed via `mach try fuzzy`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "TRY_SELECTOR": "fuzzy"
+      },
+      "gecko-profile": true,
+      "gecko-profile-features": "nostacksampling,cpu",
+      "rebuild": 5,
+      "tasks": [
+          "test/foo-debug",
+          "test/foo-opt"
+      ],
+      "version": 1
+  }
+  
+Check whether the gecko-profile flags can be used from a preset, and check
+dashes vs underscores (presets save with underscores to match ArgumentParser
+settings; everything else uses dashes.)
+
+  $ ./mach try fuzzy $testargs --save profile -q "'foo" --rebuild 5 --gecko-profile-features=nostacksampling,cpu
+  preset saved, run with: --preset=profile
+
+  $ ./mach try fuzzy $testargs --preset profile
+  Commit message:
+  Fuzzy query='foo
+  
+  Pushed via `mach try fuzzy`
+  Calculated try_task_config.json:
+  {
+      "env": {
+          "TRY_SELECTOR": "fuzzy"
+      },
+      "gecko-profile": true,
+      "gecko-profile-features": "nostacksampling,cpu",
+      "rebuild": 5,
+      "tasks": [
+          "test/foo-debug",
+          "test/foo-opt"
+      ],
+      "version": 1
+  }
+  
+  $ EDITOR=cat ./mach try fuzzy $testargs --edit-preset profile
+  bar:
+    dry_run: true
+    no_artifact: true
+    platforms:
+    - win32
+    selector: syntax
+    tags:
+    - bar
+    talos:
+    - all
+    tests:
+    - none
+  baz:
+    dry_run: true
+    no_artifact: true
+    query:
+    - '''foo'
+    rebuild: 5
+    selector: fuzzy
+  foo:
+    no_artifact: true
+    platforms:
+    - linux
+    selector: syntax
+    tags:
+    - foo
+    talos:
+    - none
+    tests:
+    - mochitests
+  profile:
+    dry_run: true
+    gecko_profile_features: nostacksampling,cpu
+    no_artifact: true
+    query:
+    - '''foo'
+    rebuild: 5
+    selector: fuzzy
+
+  $ rm $MOZBUILD_STATE_PATH/try_presets.yml
diff --git a/tools/tryselect/test/test_presets.py b/tools/tryselect/test/test_presets.py
new file mode 100644
index 0000000000..89cc810808
--- /dev/null
+++ b/tools/tryselect/test/test_presets.py
@@ -0,0 +1,58 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import mozunit
+import pytest
+
+TASKS = [
+    {
+        "kind": "build",
+        "label": "build-windows",
+        "attributes": {
+            "build_platform": "windows",
+        },
+    },
+    {
+        "kind": "test",
+        "label": "test-windows-mochitest-e10s",
+        "attributes": {
+            "unittest_suite": "mochitest",
+            "unittest_flavor": "browser-chrome",
+            "mochitest_try_name": "mochitest",
+        },
+    },
+]
+
+
+@pytest.fixture(autouse=True)
+def skip_taskgraph_generation(monkeypatch, tg):
+    def fake_generate_tasks(*args, **kwargs):
+        return tg
+
+    from tryselect import tasks
+
+    monkeypatch.setattr(tasks, "generate_tasks", fake_generate_tasks)
+
+
+@pytest.mark.xfail(
+    strict=False, reason="Bug 1635204: " "test_shared_presets[sample-suites] is flaky"
+)
+def test_shared_presets(run_mach, shared_name, shared_preset):
+    """This test makes sure that we don't break any of the in-tree presets when
+    renaming/removing variables in any of the selectors.
+    """
+    assert "description" in shared_preset
+    assert "selector" in shared_preset
+
+    selector = shared_preset["selector"]
+    if selector == "fuzzy":
+        assert "query" in shared_preset
+        assert isinstance(shared_preset["query"], list)
+
+    # Run the preset and assert there were no exceptions.
+    assert run_mach(["try", "--no-push", "--preset", shared_name]) == 0
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/tools/tryselect/test/test_release.py b/tools/tryselect/test/test_release.py
new file mode 100644
index 0000000000..a1a0d348b2
--- /dev/null
+++ b/tools/tryselect/test/test_release.py
@@ -0,0 +1,43 @@
+# Any copyright is dedicated to the Public Domain.
+# https://creativecommons.org/publicdomain/zero/1.0/
+
+from textwrap import dedent
+
+import mozunit
+
+
+def test_release(run_mach, capfd):
+    cmd = [
+        "try",
+        "release",
+        "--no-push",
+        "--version=97.0",
+    ]
+    assert run_mach(cmd) == 0
+
+    output = capfd.readouterr().out
+    print(output)
+
+    expected = dedent(
+        """
+        Commit message:
+        staging release: 97.0
+
+        Pushed via `mach try release`
+        Calculated try_task_config.json:
+        {
+            "parameters": {
+                "optimize_target_tasks": true,
+                "release_type": "release",
+                "target_tasks_method": "staging_release_builds"
+            },
+            "version": 2
+        }
+
+    """
+    ).lstrip()
+    assert expected in output
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/tools/tryselect/test/test_scriptworker.py b/tools/tryselect/test/test_scriptworker.py
new file mode 100644
index 0000000000..e25279ace4
--- /dev/null
+++ b/tools/tryselect/test/test_scriptworker.py
@@ -0,0 +1,39 @@
+# Any copyright is dedicated to the Public Domain.
+# https://creativecommons.org/publicdomain/zero/1.0/
+
+import re
+from textwrap import dedent
+
+import mozunit
+
+
+def test_release(run_mach, capfd):
+    cmd = [
+        "try",
+        "scriptworker",
+        "--no-push",
+        "tree",
+    ]
+    assert run_mach(cmd) == 0
+
+    output = capfd.readouterr().out
+    print(output)
+
+    expected = re.compile(
+        dedent(
+            r"""
+        Pushed via `mach try scriptworker`
+        Calculated try_task_config.json:
+        {
+            "parameters": {
+                "app_version": "\d+\.\d+",
+                "build_number": \d+,
+    """
+        ).lstrip(),
+        re.MULTILINE,
+    )
+    assert expected.search(output)
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/tools/tryselect/test/test_task_configs.py b/tools/tryselect/test/test_task_configs.py
new file mode 100644
index 0000000000..6c0eeadaa6
--- /dev/null
+++ b/tools/tryselect/test/test_task_configs.py
@@ -0,0 +1,144 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import inspect
+import subprocess
+from argparse import ArgumentParser
+from textwrap import dedent
+
+import mozunit
+import pytest
+from tryselect.task_config import Pernosco, all_task_configs
+
+# task configs have a list of tests of the form (input, expected)
+TASK_CONFIG_TESTS = {
+    "artifact": [
+        (["--no-artifact"], None),
+        (["--artifact"], {"use-artifact-builds": True}),
+    ],
+    "chemspill-prio": [
+        ([], None),
+        (["--chemspill-prio"], {"chemspill-prio": {}}),
+    ],
+    "env": [
+        ([], None),
+        (["--env", "foo=bar", "--env", "num=10"], {"env": {"foo": "bar", "num": "10"}}),
+    ],
+    "path": [
+        ([], None),
+        (
+            ["dom/indexedDB"],
+            {"env": {"MOZHARNESS_TEST_PATHS": '{"xpcshell": ["dom/indexedDB"]}'}},
+        ),
+        (
+            ["dom/indexedDB", "testing"],
+            {
+                "env": {
+                    "MOZHARNESS_TEST_PATHS": '{"xpcshell": ["dom/indexedDB", "testing"]}'
+                }
+            },
+        ),
+        (["invalid/path"], SystemExit),
+    ],
+    "pernosco": [
+        ([], None),
+    ],
+    "rebuild": [
+        ([], None),
+        (["--rebuild", "10"], {"rebuild": 10}),
+        (["--rebuild", "1"], SystemExit),
+        (["--rebuild", "21"], SystemExit),
+    ],
+    "worker-overrides": [
+        ([], None),
+        (
+            ["--worker-override", "alias=worker/pool"],
+            {"worker-overrides": {"alias": "worker/pool"}},
+        ),
+        (
+            [
+                "--worker-override",
+                "alias=worker/pool",
+                "--worker-override",
+                "alias=other/pool",
+            ],
+            SystemExit,
+        ),
+        (
+            ["--worker-suffix", "b-linux=-dev"],
+            {"worker-overrides": {"b-linux": "gecko-1/b-linux-dev"}},
+        ),
+        (
+            [
+                "--worker-override",
+                "b-linux=worker/pool" "--worker-suffix",
+                "b-linux=-dev",
+            ],
+            SystemExit,
+        ),
+    ],
+}
+
+
+@pytest.fixture
+def config_patch_resolver(patch_resolver):
+    def inner(paths):
+        patch_resolver(
+            [], [{"flavor": "xpcshell", "srcdir_relpath": path} for path in paths]
+        )
+
+    return inner
+
+
+def test_task_configs(config_patch_resolver, task_config, args, expected):
+    parser = ArgumentParser()
+
+    cfg = all_task_configs[task_config]()
+    cfg.add_arguments(parser)
+
+    if inspect.isclass(expected) and issubclass(expected, BaseException):
+        with pytest.raises(expected):
+            args = parser.parse_args(args)
+            if task_config == "path":
+                config_patch_resolver(**vars(args))
+
+            cfg.try_config(**vars(args))
+    else:
+        args = parser.parse_args(args)
+        if task_config == "path":
+            config_patch_resolver(**vars(args))
+        assert cfg.try_config(**vars(args)) == expected
+
+
+@pytest.fixture
+def patch_pernosco_email_check(monkeypatch):
+    def inner(val):
+        def fake_check_output(*args, **kwargs):
+            return val
+
+        monkeypatch.setattr(subprocess, "check_output", fake_check_output)
+
+    return inner
+
+
+def test_pernosco(patch_pernosco_email_check):
+    patch_pernosco_email_check(
+        dedent(
+            """
+        user foobar@mozilla.com
+        hostname hg.mozilla.com
+    """
+        )
+    )
+
+    parser = ArgumentParser()
+
+    cfg = Pernosco()
+    cfg.add_arguments(parser)
+    args = parser.parse_args(["--pernosco"])
+    assert cfg.try_config(**vars(args)) == {"env": {"PERNOSCO": "1"}}
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/tools/tryselect/test/test_tasks.py b/tools/tryselect/test/test_tasks.py
new file mode 100644
index 0000000000..cdf8cf84c1
--- /dev/null
+++ b/tools/tryselect/test/test_tasks.py
@@ -0,0 +1,93 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import os
+
+import mozunit
+import pytest
+from tryselect.tasks import cache_key, filter_tasks_by_paths, resolve_tests_by_suite
+
+
+def test_filter_tasks_by_paths(patch_resolver):
+    tasks = ["foobar/xpcshell-1", "foobar/mochitest", "foobar/xpcshell"]
+
+    patch_resolver(["xpcshell"], {})
+    assert list(filter_tasks_by_paths(tasks, "dummy")) == []
+
+    patch_resolver([], [{"flavor": "xpcshell"}])
+    assert list(filter_tasks_by_paths(tasks, "dummy")) == [
+        "foobar/xpcshell-1",
+        "foobar/xpcshell",
+    ]
+
+
+@pytest.mark.parametrize(
+    "input, tests, expected",
+    (
+        pytest.param(
+            ["xpcshell.js"],
+            [{"flavor": "xpcshell", "srcdir_relpath": "xpcshell.js"}],
+            {"xpcshell": ["xpcshell.js"]},
+            id="single test",
+        ),
+        pytest.param(
+            ["xpcshell.ini"],
+            [
+                {
+                    "flavor": "xpcshell",
+                    "srcdir_relpath": "xpcshell.js",
+                    "manifest_relpath": "xpcshell.ini",
+                },
+            ],
+            {"xpcshell": ["xpcshell.ini"]},
+            id="single manifest",
+        ),
+        pytest.param(
+            ["xpcshell.js", "mochitest.js"],
+            [
+                {"flavor": "xpcshell", "srcdir_relpath": "xpcshell.js"},
+                {"flavor": "mochitest", "srcdir_relpath": "mochitest.js"},
+            ],
+            {
+                "xpcshell": ["xpcshell.js"],
+                "mochitest-plain": ["mochitest.js"],
+            },
+            id="two tests",
+        ),
+        pytest.param(
+            ["test/xpcshell.ini"],
+            [
+                {
+                    "flavor": "xpcshell",
+                    "srcdir_relpath": "test/xpcshell.js",
+                    "manifest_relpath": os.path.join("test", "xpcshell.ini"),
+                },
+            ],
+            {"xpcshell": ["test/xpcshell.ini"]},
+            id="mismatched path separators",
+        ),
+    ),
+)
+def test_resolve_tests_by_suite(patch_resolver, input, tests, expected):
+    patch_resolver([], tests)
+    assert resolve_tests_by_suite(input) == expected
+
+
+@pytest.mark.parametrize(
+    "attr,params,disable_target_task_filter,expected",
+    (
+        ("target_task_set", None, False, "target_task_set"),
+        ("target_task_set", {"project": "autoland"}, False, "target_task_set"),
+        ("target_task_set", {"project": "mozilla-central"}, False, "target_task_set"),
+        ("target_task_set", None, True, "target_task_set-uncommon"),
+        ("full_task_set", {"project": "pine"}, False, "full_task_set-pine"),
+        ("full_task_set", None, True, "full_task_set"),
+    ),
+)
+def test_cache_key(attr, params, disable_target_task_filter, expected):
+    assert cache_key(attr, params, disable_target_task_filter) == expected
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/tools/tryselect/try_presets.yml b/tools/tryselect/try_presets.yml
new file mode 100644
index 0000000000..8351afefe2
--- /dev/null
+++ b/tools/tryselect/try_presets.yml
@@ -0,0 +1,218 @@
+---
+# Presets defined here will be available to all users. Run them with:
+#   $ mach try --preset <name>
+#
+# If editing this file, make sure to run:
+#   $ mach python-test tools/tryselect/test/test_presets.py
+#
+# Descriptions are required. Please keep this in alphabetical order.
+
+# yamllint disable rule:line-length
+
+builds:
+    selector: fuzzy
+    description: >-
+        Run builds without any of the extras.
+    query:
+        - "^build- !fuzzing !notarization !reproduced !rusttests !signing !upload-symbols"
+
+builds-debug:
+    selector: fuzzy
+    description: >-
+        Run the bare minimum of debug build jobs to ensure builds work on
+        all tier-1 platforms.
+    query:
+        - "^build- 'debug !fuzzing !rusttests !signing !plain !asan !tsan !noopt !toolchain !upload-symbols"
+
+builds-debugopt:
+    selector: fuzzy
+    description: >-
+        Run the bare minimum of debug and opt build jobs to ensure builds work on
+        all tier-1 platforms.
+    query:
+        - "^build- !fuzzing !rusttests !signing !plain !asan !tsan !noopt !toolchain !upload-symbols"
+
+devtools:
+    selector: fuzzy
+    description: >-
+        Runs the tests relevant to the Firefox Devtools
+    query:
+        - "'node-debugger | 'node-devtools"
+        - "'mozlint-eslint"
+        # Windows: skip jobs on asan and 32 bits platforms
+        - "'mochitest-devtools-chrome | 'mochitest-chrome-1proc 'windows10 !asan !-32"
+        # macos: no extra platform to filter out
+        - "'mochitest-devtools-chrome | 'mochitest-chrome-1proc 'macosx"
+        # Linux is being named "linux1804" and may change over time, so use a more flexible search
+        - "'mochitest-devtools-chrome | 'mochitest-chrome-1proc 'linux '64-qr/ !swr"
+        - "'xpcshell 'linux !nofis '64-qr/"
+
+devtools-linux:
+    selector: fuzzy
+    description: >-
+        Runs the tests relevant to the Firefox Devtools, on Linux only.
+    query:
+        - "'node-debugger | 'node-devtools"
+        - "'mozlint-eslint"
+        - "'mochitest-devtools-chrome | 'mochitest-chrome-1proc 'linux '64-qr/ !swr"
+        - "'xpcshell 'linux !nofis '64-qr/"
+
+fpush-linux-android:
+    selector: fuzzy
+    description: >-
+        Runs correctness test suites on Linux and Android emulator platforms, as
+        well as builds across main platforms. The resulting jobs on TreeHerder
+        used to end up looking like a "F" shape (not so much these days) and so
+        this is typically referred to as an F-push. This is useful to do as a
+        general sanity check on changes to cross-platform Gecko code where you
+        unsure of what tests might be affected. Linux and Android (emulator)
+        test coverage are relatively cheap to run and cover a lot of the
+        codebase, while the builds on other platforms catch compilation problems
+        that might result from only building locally on one platform.
+    query:
+        - "'test-linux1804 'debug- !-shippable !-asan"
+        - "'test-android-em 'debug"
+        - "^build !-shippable !-signing !-asan !-fuzzing !-rusttests !-base-toolchain !-aar-"
+
+geckodriver:
+    selector: fuzzy
+    description: >-
+        Runs the tests relevant to geckodriver, which implements the WebDriver
+        specification. This preset can be filtered down further to limit it to
+        a specific platform or other tasks only. For example:
+        |mach try --preset geckodriver -xq "'linux"|
+    query:
+        - "'rusttests"
+        - "'platform 'wdspec 'debug 'nofis"
+        - "'browsertime 'amazon 'shippable 'firefox 'nofis"
+
+media-full:
+    selector: fuzzy
+    description: >-
+        Runs tests that exercise media playback and WebRTC code.
+    query:
+        - "mochitest-media !dfpi !nofis"
+        - "mochitest-browser-chrome !dfpi !nofis !a11y"
+        - "mochitest-browser-media"
+        - "web-platform-tests !dfpi !nofis"
+        - "crashtest !wdspec !nofis"
+        - "'gtest"
+
+perf:
+    selector: fuzzy
+    description: >-
+        Runs all performance (raptor and talos) tasks across all platforms.
+        This preset can be filtered down further (e.g to limit it to a specific
+        platform) via |mach try --preset perf -xq "'windows"|.
+
+        Android hardware platforms are excluded due to resource limitations.
+    query:
+        - "^test- !android-hw 'raptor | 'talos"
+    rebuild: 5
+
+perf-chrome:
+    description: >-
+        Runs the talos tests most likely to change when making a change to
+        the browser chrome. This skips a number of talos jobs that are unlikely
+        to be affected in order to conserve resources.
+    query:
+        - "opt-talos- 'chrome | 'svg | 'session | 'tabswitch | 'other | 'g5"
+    rebuild: 6
+    selector: fuzzy
+
+remote-protocol:
+    selector: fuzzy
+    description: >-
+        Runs the tests relevant to the Remote protocol, which underpins
+        many test harnesses as well as our CDP and WebDriver implementations.
+        This preset can be filtered down further to limit it to a specific
+        platform or to opt/debug tasks only. For example:
+        |mach try --preset remote-protocol -xq "'linux 'opt"|
+    query:
+        - "'awsy-base"
+        - "'firefox-ui"
+        - "'marionette !swr | harness"
+        - "'mochitest-browser !spi !swr !nofis '-1$"
+        - "'mochitest-remote !spi !swr"
+        - "'platform 'reftest !swr !nofis | 'android !-lite -1$"
+        - "'platform 'wdspec !swr"
+        - "'platform !reftest !wdspec !swr !nofis | 'android !-lite -1$"
+        - "'puppeteer"
+        - "'reftest !platform !gpu !swr !no-accel !nofis | 'android !-lite -1$"
+        - "'xpcshell !spi !tsan !-lite"
+
+sample-suites:
+    selector: fuzzy
+    description: >-
+        Runs one chunk of every test suite plus all suites that aren't chunked.
+        It is useful for testing infrastructure changes that can affect the
+        harnesses themselves but are unlikely to break specific tests.
+    query:
+        - ^test- -1$
+        # Only run a single talos + raptor suite per platform
+        - ^test- !1$ !2$ !3$ !4$ !5$ !6$ !7$ !8$ !9$ !0$ !raptor !talos
+        - ^test- 'raptor-speedometer | 'talos-g1
+
+sm-shell-all:
+    selector: fuzzy
+    description: <-
+        Runs a set of tests aimed to give a reasonable level of confidence for
+        basic SpiderMonkey changes (shell only), all platforms
+    query:
+        - "'spidermonkey | 'shell-haz"
+        - "!shippable !android 'jittest"  # macosx64 jittests
+
+sm-shell:
+    selector: fuzzy
+    description: <-
+        Runs a set of tests aimed to give a reasonable level of confidence for
+        basic SpiderMonkey changes (shell only) (linux only)
+    query:
+        - "!win !osx 'spidermonkey | 'shell-haz"
+
+
+sm-all:
+    selector: fuzzy
+    description: <-
+        Runs a set of tests aimed to give a reasonable level of confidence for
+        basic SpiderMonkey changes, including those that would require a
+        browser build.
+    query:
+        - "'spidermonkey | 'hazard"
+        - "!android !asan !shippable 'xpcshell"
+        - "!android !asan !shippable 'jsreftest"
+        - "!shippable !android 'jittest"  # macosx64 jittests
+
+webrender:
+    selector: fuzzy
+    description: >-
+        Runs the conformance tests relevant to WebRender.
+    query:
+        - "!talos !raptor !shippable !asan '-qr"
+        - "^webrender-"
+
+webrender-reftests:
+    selector: fuzzy
+    description: >-
+        Runs the reftests relevant to WebRender.
+    query:
+        - "!talos !raptor !shippable !asan !nofis 'reftest"
+
+webrender-reftests-linux:
+    selector: fuzzy
+    description: >-
+        Runs the reftests relevant to WebRender on linux only.
+    query:
+        - "!talos !raptor !shippable !asan !nofis 'linux 'reftest"
+
+webrender-perf:
+    selector: fuzzy
+    description: >-
+        Runs the performance tests relevant to WebRender.
+    query:
+        - "'-qr 'svgr"
+        - "'-qr 'g1"
+        - "'-qr 'g4"
+        - "'-qr 'tp5"
+        - "'-qr 'talos-webgl"
+        - "'-qr 'motionmark-animometer"
diff --git a/tools/tryselect/util/__init__.py b/tools/tryselect/util/__init__.py
new file mode 100644
index 0000000000..c580d191c1
--- /dev/null
+++ b/tools/tryselect/util/__init__.py
@@ -0,0 +1,3 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
diff --git a/tools/tryselect/util/dicttools.py b/tools/tryselect/util/dicttools.py
new file mode 100644
index 0000000000..465e4a43de
--- /dev/null
+++ b/tools/tryselect/util/dicttools.py
@@ -0,0 +1,50 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+import copy
+
+
+def merge_to(source, dest):
+    """
+    Merge dict and arrays (override scalar values)
+
+    Keys from source override keys from dest, and elements from lists in source
+    are appended to lists in dest.
+
+    :param dict source: to copy from
+    :param dict dest: to copy to (modified in place)
+    """
+
+    for key, value in source.items():
+        # Override mismatching or empty types
+        if type(value) != type(dest.get(key)):  # noqa
+            dest[key] = source[key]
+            continue
+
+        # Merge dict
+        if isinstance(value, dict):
+            merge_to(value, dest[key])
+            continue
+
+        if isinstance(value, list):
+            dest[key] = dest[key] + source[key]
+            continue
+
+        dest[key] = source[key]
+
+    return dest
+
+
+def merge(*objects):
+    """
+    Merge the given objects, using the semantics described for merge_to, with
+    objects later in the list taking precedence.  From an inheritance
+    perspective, "parents" should be listed before "children".
+
+    Returns the result without modifying any arguments.
+    """
+    if len(objects) == 1:
+        return copy.deepcopy(objects[0])
+    return merge_to(objects[-1], merge(*objects[:-1]))
diff --git a/tools/tryselect/util/estimates.py b/tools/tryselect/util/estimates.py
new file mode 100644
index 0000000000..634b1de2a2
--- /dev/null
+++ b/tools/tryselect/util/estimates.py
@@ -0,0 +1,126 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+import json
+import os
+from datetime import datetime, timedelta
+
+TASK_DURATION_CACHE = "task_duration_history.json"
+GRAPH_QUANTILE_CACHE = "graph_quantile_cache.csv"
+TASK_DURATION_TAG_FILE = "task_duration_tag.json"
+
+
+def find_all_dependencies(graph, tasklist):
+    all_dependencies = dict()
+
+    def find_dependencies(task):
+        dependencies = set()
+        if task in all_dependencies:
+            return all_dependencies[task]
+        if task not in graph:
+            # Don't add tasks (and so durations) for
+            # things optimised out.
+            return dependencies
+        dependencies.add(task)
+        for dep in graph.get(task, list()):
+            all_dependencies[dep] = find_dependencies(dep)
+            dependencies.update(all_dependencies[dep])
+        return dependencies
+
+    full_deps = set()
+    for task in tasklist:
+        full_deps.update(find_dependencies(task))
+
+    # Since these have been asked for, they're not inherited dependencies.
+    return sorted(full_deps - set(tasklist))
+
+
+def find_longest_path(graph, tasklist, duration_data):
+
+    dep_durations = dict()
+
+    def find_dependency_durations(task):
+        if task in dep_durations:
+            return dep_durations[task]
+
+        durations = [find_dependency_durations(dep) for dep in graph.get(task, list())]
+        durations.append(0.0)
+        md = max(durations) + duration_data.get(task, 0.0)
+        dep_durations[task] = md
+        return md
+
+    longest_paths = [find_dependency_durations(task) for task in tasklist]
+    # Default in case there are no tasks
+    if longest_paths:
+        return max(longest_paths)
+    else:
+        return 0
+
+
+def determine_percentile(quantiles_file, duration):
+
+    duration = duration.total_seconds()
+
+    with open(quantiles_file) as f:
+        f.readline()  # skip header
+        boundaries = [float(l.strip()) for l in f.readlines()]
+
+    boundaries.sort()
+    for i, v in enumerate(boundaries):
+        if duration < v:
+            break
+    # Estimate percentile from len(boundaries)-quantile
+    return int(100 * i / len(boundaries))
+
+
+def task_duration_data(cache_dir):
+    with open(os.path.join(cache_dir, TASK_DURATION_CACHE)) as f:
+        return json.load(f)
+
+
+def duration_summary(graph_cache_file, tasklist, cache_dir):
+    durations = task_duration_data(cache_dir)
+
+    graph = dict()
+    if graph_cache_file:
+        with open(graph_cache_file) as f:
+            graph = json.load(f)
+    dependencies = find_all_dependencies(graph, tasklist)
+    longest_path = find_longest_path(graph, tasklist, durations)
+    dependency_duration = 0.0
+    for task in dependencies:
+        dependency_duration += int(durations.get(task, 0.0))
+
+    total_requested_duration = 0.0
+    for task in tasklist:
+        duration = int(durations.get(task, 0.0))
+        total_requested_duration += duration
+    output = dict()
+
+    total_requested_duration = timedelta(seconds=total_requested_duration)
+    total_dependency_duration = timedelta(seconds=dependency_duration)
+
+    output["selected_duration"] = total_requested_duration
+    output["dependency_duration"] = total_dependency_duration
+    output["dependency_count"] = len(dependencies)
+    output["selected_count"] = len(tasklist)
+
+    percentile = None
+    graph_quantile_cache = os.path.join(cache_dir, GRAPH_QUANTILE_CACHE)
+    if os.path.isfile(graph_quantile_cache):
+        percentile = determine_percentile(
+            graph_quantile_cache, total_dependency_duration + total_requested_duration
+        )
+    if percentile:
+        output["percentile"] = percentile
+
+    output["wall_duration_seconds"] = timedelta(seconds=int(longest_path))
+    output["eta_datetime"] = datetime.now() + timedelta(seconds=longest_path)
+
+    output["task_durations"] = {
+        task: int(durations.get(task, 0.0)) for task in tasklist
+    }
+
+    return output
diff --git a/tools/tryselect/util/fzf.py b/tools/tryselect/util/fzf.py
new file mode 100644
index 0000000000..a111177812
--- /dev/null
+++ b/tools/tryselect/util/fzf.py
@@ -0,0 +1,423 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+import os
+import platform
+import shutil
+import subprocess
+import sys
+from distutils.spawn import find_executable
+
+import mozfile
+import six
+from gecko_taskgraph.target_tasks import filter_by_uncommon_try_tasks
+from mach.util import get_state_dir
+from mozboot.util import http_download_and_save
+from mozbuild.base import MozbuildObject
+from mozterm import Terminal
+from packaging.version import Version
+
+from ..push import check_working_directory
+from ..tasks import generate_tasks
+from ..util.manage_estimates import (
+    download_task_history_data,
+    make_trimmed_taskgraph_cache,
+)
+
+terminal = Terminal()
+
+here = os.path.abspath(os.path.dirname(__file__))
+build = MozbuildObject.from_environment(cwd=here)
+
+PREVIEW_SCRIPT = os.path.join(build.topsrcdir, "tools/tryselect/selectors/preview.py")
+
+FZF_MIN_VERSION = "0.20.0"
+FZF_CURRENT_VERSION = "0.29.0"
+
+# It would make more sense to have the full filename be the key; but that makes
+# the line too long and ./mach lint and black can't agree about what to about that.
+# You can get these from the github release, e.g.
+#          https://github.com/junegunn/fzf/releases/download/0.24.1/fzf_0.24.1_checksums.txt
+# However the darwin releases may not be included, so double check you have everything
+FZF_CHECKSUMS = {
+    "linux_armv5.tar.gz": "61d3c2aa77b977ba694836fd1134da9272bd97ee490ececaf87959b985820111",
+    "linux_armv6.tar.gz": "db6b30fcbbd99ac4cf7e3ff6c5db1d3c0afcbe37d10ec3961bdc43e8c4f2e4f9",
+    "linux_armv7.tar.gz": "ed86f0e91e41d2cea7960a78e3eb175dc2a5fc1510380c195d0c3559bfdc701c",
+    "linux_arm64.tar.gz": "47988d8b68905541cbc26587db3ed1cfa8bc3aa8da535120abb4229b988f259e",
+    "linux_amd64.tar.gz": "0106f458b933be65edb0e8f0edb9a16291a79167836fd26a77ff5496269b5e9a",
+    "windows_armv5.zip": "08eaac45b3600d82608d292c23e7312696e7e11b6278b292feba25e8eb91c712",
+    "windows_armv6.zip": "8b6618726a9d591a45120fddebc29f4164e01ce6639ed9aa8fc79ab03eefcfed",
+    "windows_armv7.zip": "c167117b4c08f4f098446291115871ce5f14a8a8b22f0ca70e1b4342452ab5d7",
+    "windows_arm64.zip": "0cda7bf68850a3e867224a05949612405e63a4421d52396c1a6c9427d4304d72",
+    "windows_amd64.zip": "f0797ceee089017108c80b09086c71b8eec43d4af11ce939b78b1d5cfd202540",
+    "darwin_arm64.zip": "2571b4d381f1fc691e7603bbc8113a67116da2404751ebb844818d512dd62b4b",
+    "darwin_amd64.zip": "bc541e8ae0feb94efa96424bfe0b944f746db04e22f5cccfe00709925839a57f",
+    "openbsd_amd64.tar.gz": "b62343827ff83949c09d5e2c8ca0c1198d05f733c9a779ec37edd840541ccdab",
+    "freebsd_amd64.tar.gz": "f0367f2321c070d103589c7c7eb6a771bc7520820337a6c2fbb75be37ff783a9",
+}
+
+FZF_INSTALL_MANUALLY = """
+The `mach try fuzzy` command depends on fzf. Please install it following the
+appropriate instructions for your platform:
+
+    https://github.com/junegunn/fzf#installation
+
+Only the binary is required, if you do not wish to install the shell and
+editor integrations, download the appropriate binary and put it on your $PATH:
+
+    https://github.com/junegunn/fzf/releases
+""".lstrip()
+
+FZF_COULD_NOT_DETERMINE_PLATFORM = (
+    """
+Could not automatically obtain the `fzf` binary because we could not determine
+your Operating System.
+
+""".lstrip()
+    + FZF_INSTALL_MANUALLY
+)
+
+FZF_COULD_NOT_DETERMINE_MACHINE = (
+    """
+Could not automatically obtain the `fzf` binary because we could not determine
+your machine type.  It's reported as '%s' and we don't handle that case; but fzf
+may still be available as a prebuilt binary.
+
+""".lstrip()
+    + FZF_INSTALL_MANUALLY
+)
+
+FZF_NOT_SUPPORTED_X86 = (
+    """
+We don't believe that a prebuilt binary for `fzf` if available on %s, but we
+could be wrong.
+
+""".lstrip()
+    + FZF_INSTALL_MANUALLY
+)
+
+FZF_NOT_FOUND = (
+    """
+Could not find the `fzf` binary.
+
+""".lstrip()
+    + FZF_INSTALL_MANUALLY
+)
+
+FZF_VERSION_FAILED = (
+    """
+Could not obtain the 'fzf' version; we require version > 0.20.0 for some of
+the features.
+
+""".lstrip()
+    + FZF_INSTALL_MANUALLY
+)
+
+FZF_INSTALL_FAILED = (
+    """
+Failed to install fzf.
+
+""".lstrip()
+    + FZF_INSTALL_MANUALLY
+)
+
+FZF_HEADER = """
+For more shortcuts, see {t.italic_white}mach help try fuzzy{t.normal} and {t.italic_white}man fzf
+{shortcuts}
+""".strip()
+
+fzf_shortcuts = {
+    "ctrl-a": "select-all",
+    "ctrl-d": "deselect-all",
+    "ctrl-t": "toggle-all",
+    "alt-bspace": "beginning-of-line+kill-line",
+    "?": "toggle-preview",
+}
+
+fzf_header_shortcuts = [
+    ("select", "tab"),
+    ("accept", "enter"),
+    ("cancel", "ctrl-c"),
+    ("select-all", "ctrl-a"),
+    ("cursor-up", "up"),
+    ("cursor-down", "down"),
+]
+
+
+def run_cmd(cmd, cwd=None):
+    is_win = platform.system() == "Windows"
+    return subprocess.call(cmd, cwd=cwd, shell=True if is_win else False)
+
+
+def get_fzf_platform():
+    if platform.machine() in ["i386", "i686"]:
+        print(FZF_NOT_SUPPORTED_X86 % platform.machine())
+        sys.exit(1)
+
+    if platform.system().lower() == "windows":
+        if platform.machine().lower() in ["x86_64", "amd64"]:
+            return "windows_amd64.zip"
+        elif platform.machine().lower() == "arm64":
+            return "windows_arm64.zip"
+        else:
+            print(FZF_COULD_NOT_DETERMINE_MACHINE % platform.machine())
+            sys.exit(1)
+    elif platform.system().lower() == "darwin":
+        if platform.machine().lower() in ["x86_64", "amd64"]:
+            return "darwin_amd64.zip"
+        elif platform.machine().lower() == "arm64":
+            return "darwin_arm64.zip"
+        else:
+            print(FZF_COULD_NOT_DETERMINE_MACHINE % platform.machine())
+            sys.exit(1)
+    elif platform.system().lower() == "linux":
+        if platform.machine().lower() in ["x86_64", "amd64"]:
+            return "linux_amd64.tar.gz"
+        elif platform.machine().lower() == "arm64":
+            return "linux_arm64.tar.gz"
+        else:
+            print(FZF_COULD_NOT_DETERMINE_MACHINE % platform.machine())
+            sys.exit(1)
+    else:
+        print(FZF_COULD_NOT_DETERMINE_PLATFORM)
+        sys.exit(1)
+
+
+def get_fzf_state_dir():
+    return os.path.join(get_state_dir(), "fzf")
+
+
+def get_fzf_filename():
+    return "fzf-%s-%s" % (FZF_CURRENT_VERSION, get_fzf_platform())
+
+
+def get_fzf_download_link():
+    return "https://github.com/junegunn/fzf/releases/download/%s/%s" % (
+        FZF_CURRENT_VERSION,
+        get_fzf_filename(),
+    )
+
+
+def clean_up_state_dir():
+    """
+    We used to have a checkout of fzf that we would update.
+    Now we only download the bin and cpin the hash; so if
+    we find the old git checkout, wipe it
+    """
+
+    fzf_path = os.path.join(get_state_dir(), "fzf")
+    git_path = os.path.join(fzf_path, ".git")
+    if os.path.isdir(git_path):
+        shutil.rmtree(fzf_path, ignore_errors=True)
+
+    # Also delete any existing fzf binary
+    fzf_bin = find_executable("fzf", fzf_path)
+    if fzf_bin:
+        mozfile.remove(fzf_bin)
+
+    # Make sure the state dir is present
+    if not os.path.isdir(fzf_path):
+        os.makedirs(fzf_path)
+
+
+def download_and_install_fzf():
+    clean_up_state_dir()
+    download_link = get_fzf_download_link()
+    download_file = get_fzf_filename()
+    download_destination_path = get_fzf_state_dir()
+    download_destination_file = os.path.join(download_destination_path, download_file)
+    http_download_and_save(
+        download_link, download_destination_file, FZF_CHECKSUMS[get_fzf_platform()]
+    )
+
+    mozfile.extract(download_destination_file, download_destination_path)
+    mozfile.remove(download_destination_file)
+
+
+def get_fzf_version(fzf_bin):
+    cmd = [fzf_bin, "--version"]
+    try:
+        fzf_version = subprocess.check_output(cmd)
+    except subprocess.CalledProcessError:
+        print(FZF_VERSION_FAILED)
+        sys.exit(1)
+
+    # Some fzf versions have extra, e.g 0.18.0 (ff95134)
+    fzf_version = six.ensure_text(fzf_version.split()[0])
+
+    return fzf_version
+
+
+def should_force_fzf_update(fzf_bin):
+    fzf_version = get_fzf_version(fzf_bin)
+
+    # 0.20.0 introduced passing selections through a temporary file,
+    # which is good for large ctrl-a actions.
+    if Version(fzf_version) < Version(FZF_MIN_VERSION):
+        print("fzf version is old, you must update to use ./mach try fuzzy.")
+        return True
+    return False
+
+
+def fzf_bootstrap(update=False):
+    """
+    Bootstrap fzf if necessary and return path to the executable.
+
+    This function is a bit complicated. We fetch a new version of fzf if:
+    1) an existing fzf is too outdated
+    2) the user says --update and we are behind the recommended version
+    3) no fzf can be found and
+      3a) user passes --update
+      3b) user agrees to a prompt
+
+    """
+    fzf_path = get_fzf_state_dir()
+
+    fzf_bin = find_executable("fzf")
+    if not fzf_bin:
+        fzf_bin = find_executable("fzf", fzf_path)
+
+    if fzf_bin and should_force_fzf_update(fzf_bin):  # Case (1)
+        update = True
+
+    if fzf_bin and not update:
+        return fzf_bin
+
+    elif fzf_bin and update:
+        # Case 2
+        fzf_version = get_fzf_version(fzf_bin)
+        if Version(fzf_version) < Version(FZF_CURRENT_VERSION) and update:
+            # Bug 1623197: We only want to run fzf's `install` if it's not in the $PATH
+            # Swap to os.path.commonpath when we're not on Py2
+            if fzf_bin and update and not fzf_bin.startswith(fzf_path):
+                print(
+                    "fzf installed somewhere other than {}, please update manually".format(
+                        fzf_path
+                    )
+                )
+                sys.exit(1)
+
+            download_and_install_fzf()
+            print("Updated fzf to {}".format(FZF_CURRENT_VERSION))
+        else:
+            print("fzf is the recommended version and does not need an update")
+
+    else:  # not fzf_bin:
+        if not update:
+            # Case 3b
+            install = input("Could not detect fzf, install it now? [y/n]: ")
+            if install.lower() != "y":
+                return
+
+        # Case 3a and 3b-fall-through
+        download_and_install_fzf()
+        fzf_bin = find_executable("fzf", fzf_path)
+        print("Installed fzf to {}".format(fzf_path))
+
+    return fzf_bin
+
+
+def format_header():
+    shortcuts = []
+    for action, key in fzf_header_shortcuts:
+        shortcuts.append(
+            "{t.white}{action}{t.normal}: {t.yellow}<{key}>{t.normal}".format(
+                t=terminal, action=action, key=key
+            )
+        )
+    return FZF_HEADER.format(shortcuts=", ".join(shortcuts), t=terminal)
+
+
+def run_fzf(cmd, tasks):
+    env = dict(os.environ)
+    env.update(
+        {"PYTHONPATH": os.pathsep.join([p for p in sys.path if "requests" in p])}
+    )
+    proc = subprocess.Popen(
+        cmd,
+        stdout=subprocess.PIPE,
+        stdin=subprocess.PIPE,
+        env=env,
+        universal_newlines=True,
+    )
+    out = proc.communicate("\n".join(tasks))[0].splitlines()
+
+    selected = []
+    query = None
+    if out:
+        query = out[0]
+        selected = out[1:]
+    return query, selected
+
+
+def setup_tasks_for_fzf(
+    push,
+    parameters,
+    full=False,
+    disable_target_task_filter=False,
+    show_estimates=True,
+):
+    check_working_directory(push)
+    tg = generate_tasks(
+        parameters, full=full, disable_target_task_filter=disable_target_task_filter
+    )
+    all_tasks = sorted(tg.tasks.keys())
+
+    # graph_Cache created by generate_tasks, recreate the path to that file.
+    cache_dir = os.path.join(
+        get_state_dir(specific_to_topsrcdir=True), "cache", "taskgraph"
+    )
+    if full:
+        graph_cache = os.path.join(cache_dir, "full_task_graph")
+        dep_cache = os.path.join(cache_dir, "full_task_dependencies")
+        target_set = os.path.join(cache_dir, "full_task_set")
+    else:
+        graph_cache = os.path.join(cache_dir, "target_task_graph")
+        dep_cache = os.path.join(cache_dir, "target_task_dependencies")
+        target_set = os.path.join(cache_dir, "target_task_set")
+
+    if show_estimates:
+        download_task_history_data(cache_dir=cache_dir)
+        make_trimmed_taskgraph_cache(graph_cache, dep_cache, target_file=target_set)
+
+    if not full and not disable_target_task_filter:
+        # Put all_tasks into a list because it's used multiple times, and "filter()"
+        # returns a consumable iterator.
+        all_tasks = list(filter(filter_by_uncommon_try_tasks, all_tasks))
+
+    return all_tasks, dep_cache, cache_dir
+
+
+def build_base_cmd(fzf, dep_cache, cache_dir, show_estimates=True):
+    key_shortcuts = [k + ":" + v for k, v in fzf_shortcuts.items()]
+    base_cmd = [
+        fzf,
+        "-m",
+        "--bind",
+        ",".join(key_shortcuts),
+        "--header",
+        format_header(),
+        "--preview-window=right:30%",
+        "--print-query",
+    ]
+
+    if show_estimates:
+        base_cmd.extend(
+            [
+                "--preview",
+                '{} {} -g {} -s -c {} -t "{{+f}}"'.format(
+                    sys.executable, PREVIEW_SCRIPT, dep_cache, cache_dir
+                ),
+            ]
+        )
+    else:
+        base_cmd.extend(
+            [
+                "--preview",
+                '{} {} -t "{{+f}}"'.format(sys.executable, PREVIEW_SCRIPT),
+            ]
+        )
+
+    return base_cmd
diff --git a/tools/tryselect/util/manage_estimates.py b/tools/tryselect/util/manage_estimates.py
new file mode 100644
index 0000000000..23fa481228
--- /dev/null
+++ b/tools/tryselect/util/manage_estimates.py
@@ -0,0 +1,132 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+
+import json
+import os
+from datetime import datetime, timedelta
+
+import requests
+import six
+
+TASK_DURATION_URL = (
+    "https://storage.googleapis.com/mozilla-mach-data/task_duration_history.json"
+)
+GRAPH_QUANTILES_URL = (
+    "https://storage.googleapis.com/mozilla-mach-data/machtry_quantiles.csv"
+)
+from .estimates import GRAPH_QUANTILE_CACHE, TASK_DURATION_CACHE, TASK_DURATION_TAG_FILE
+
+
+def check_downloaded_history(tag_file, duration_cache, quantile_cache):
+    if not os.path.isfile(tag_file):
+        return False
+
+    try:
+        with open(tag_file) as f:
+            duration_tags = json.load(f)
+        download_date = datetime.strptime(
+            duration_tags.get("download_date"), "%Y-%M-%d"
+        )
+        if download_date < datetime.now() - timedelta(days=7):
+            return False
+    except (OSError, ValueError):
+        return False
+
+    if not os.path.isfile(duration_cache):
+        return False
+    # Check for old format version of file.
+    with open(duration_cache) as f:
+        data = json.load(f)
+        if isinstance(data, list):
+            return False
+    if not os.path.isfile(quantile_cache):
+        return False
+
+    return True
+
+
+def download_task_history_data(cache_dir):
+    """Fetch task duration data exported from BigQuery."""
+    task_duration_cache = os.path.join(cache_dir, TASK_DURATION_CACHE)
+    task_duration_tag_file = os.path.join(cache_dir, TASK_DURATION_TAG_FILE)
+    graph_quantile_cache = os.path.join(cache_dir, GRAPH_QUANTILE_CACHE)
+
+    if check_downloaded_history(
+        task_duration_tag_file, task_duration_cache, graph_quantile_cache
+    ):
+        return
+
+    try:
+        os.unlink(task_duration_tag_file)
+        os.unlink(task_duration_cache)
+        os.unlink(graph_quantile_cache)
+    except OSError:
+        print("No existing task history to clean up.")
+
+    try:
+        r = requests.get(TASK_DURATION_URL, stream=True)
+        r.raise_for_status()
+    except requests.exceptions.RequestException as exc:
+        # This is fine, the durations just won't be in the preview window.
+        print(
+            "Error fetching task duration cache from {}: {}".format(
+                TASK_DURATION_URL, exc
+            )
+        )
+        return
+
+    # The data retrieved from google storage is a newline-separated
+    # list of json entries, which Python's json module can't parse.
+    duration_data = list()
+    for line in r.text.splitlines():
+        duration_data.append(json.loads(line))
+
+    # Reformat duration data to avoid list of dicts, as this is slow in the preview window
+    duration_data = {d["name"]: d["mean_duration_seconds"] for d in duration_data}
+
+    with open(task_duration_cache, "w") as f:
+        json.dump(duration_data, f, indent=4)
+
+    try:
+        r = requests.get(GRAPH_QUANTILES_URL, stream=True)
+        r.raise_for_status()
+    except requests.exceptions.RequestException as exc:
+        # This is fine, the percentile just won't be in the preview window.
+        print(
+            "Error fetching task group percentiles from {}: {}".format(
+                GRAPH_QUANTILES_URL, exc
+            )
+        )
+        return
+
+    with open(graph_quantile_cache, "w") as f:
+        f.write(six.ensure_text(r.content))
+
+    with open(task_duration_tag_file, "w") as f:
+        json.dump({"download_date": datetime.now().strftime("%Y-%m-%d")}, f, indent=4)
+
+
+def make_trimmed_taskgraph_cache(graph_cache, dep_cache, target_file=None):
+    """Trim the taskgraph cache used for dependencies.
+
+    Speeds up the fzf preview window to less human-perceptible
+    ranges."""
+    if not os.path.isfile(graph_cache):
+        return
+
+    target_task_set = set()
+    if target_file and os.path.isfile(target_file):
+        with open(target_file) as f:
+            target_task_set = set(json.load(f).keys())
+
+    with open(graph_cache) as f:
+        graph = json.load(f)
+    graph = {
+        name: list(defn["dependencies"].values())
+        for name, defn in graph.items()
+        if name in target_task_set
+    }
+    with open(dep_cache, "w") as f:
+        json.dump(graph, f, indent=4)
diff --git a/tools/tryselect/watchman.json b/tools/tryselect/watchman.json
new file mode 100644
index 0000000000..2825e5336c
--- /dev/null
+++ b/tools/tryselect/watchman.json
@@ -0,0 +1,8 @@
+["trigger", ".",
+{
+    "name": "rebuild-taskgraph-cache",
+    "expression": ["match", "taskcluster/**", "wholename"],
+    "command": ["./mach", "python", "-c", "from tryselect.tasks import generate_tasks; generate_tasks()"],
+    "append_files": false
+}
+]