Adding upstream version 110.0.1.upstream/110.0.1upstream

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

11 files changed, 1328 insertions, 0 deletions

diff --git a/testing/mozbase/mozcrash/mozcrash/__init__.py b/testing/mozbase/mozcrash/mozcrash/__init__.py
new file mode 100644
index 0000000000..a6dfab2b24
--- /dev/null
+++ b/testing/mozbase/mozcrash/mozcrash/__init__.py
@@ -0,0 +1,9 @@
+# flake8: noqa
+# 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/.
+"""
+mozcrash is a library for getting a stack trace out of processes that have crashed
+and left behind a minidump file using the Google Breakpad library.
+"""
+from .mozcrash import *
diff --git a/testing/mozbase/mozcrash/mozcrash/mozcrash.py b/testing/mozbase/mozcrash/mozcrash/mozcrash.py
new file mode 100644
index 0000000000..fbc2f86cae
--- /dev/null
+++ b/testing/mozbase/mozcrash/mozcrash/mozcrash.py
@@ -0,0 +1,849 @@
+# 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 glob
+import json
+import os
+import re
+import shutil
+import signal
+import subprocess
+import sys
+import tempfile
+import zipfile
+from collections import namedtuple
+
+import mozfile
+import mozinfo
+import mozlog
+import six
+from redo import retriable
+
+__all__ = [
+    "check_for_crashes",
+    "check_for_java_exception",
+    "kill_and_get_minidump",
+    "log_crashes",
+    "cleanup_pending_crash_reports",
+]
+
+
+StackInfo = namedtuple(
+    "StackInfo",
+    [
+        "minidump_path",
+        "signature",
+        "stackwalk_stdout",
+        "stackwalk_stderr",
+        "stackwalk_retcode",
+        "stackwalk_errors",
+        "extra",
+        "reason",
+        "java_stack",
+    ],
+)
+
+
+def get_logger():
+    structured_logger = mozlog.get_default_logger("mozcrash")
+    if structured_logger is None:
+        return mozlog.unstructured.getLogger("mozcrash")
+    return structured_logger
+
+
+def check_for_crashes(
+    dump_directory,
+    symbols_path=None,
+    stackwalk_binary=None,
+    dump_save_path=None,
+    test_name=None,
+    quiet=False,
+    keep=False,
+):
+    """
+    Print a stack trace for minidump files left behind by a crashing program.
+
+    `dump_directory` will be searched for minidump files. Any minidump files found will
+    have `stackwalk_binary` executed on them, with `symbols_path` passed as an extra
+    argument.
+
+    `stackwalk_binary` should be a path to the minidump-stackwalk binary.
+    If `stackwalk_binary` is not set, the MINIDUMP_STACKWALK environment variable
+    will be checked and its value used if it is not empty. If neither is set, then
+    ~/.mozbuild/minidump-stackwalk/minidump-stackwalk will be used.
+
+    `symbols_path` should be a path to a directory containing symbols to use for
+    dump processing. This can either be a path to a directory containing Breakpad-format
+    symbols, or a URL to a zip file containing a set of symbols.
+
+    If `dump_save_path` is set, it should be a path to a directory in which to copy minidump
+    files for safekeeping after a stack trace has been printed. If not set, the environment
+    variable MINIDUMP_SAVE_PATH will be checked and its value used if it is not empty.
+
+    If `test_name` is set it will be used as the test name in log output. If not set the
+    filename of the calling function will be used.
+
+    If `quiet` is set, no PROCESS-CRASH message will be printed to stdout if a
+    crash is detected.
+
+    If `keep` is set, minidump files will not be removed after processing.
+
+    Returns number of minidump files found.
+    """
+
+    # try to get the caller's filename if no test name is given
+    if test_name is None:
+        try:
+            test_name = os.path.basename(sys._getframe(1).f_code.co_filename)
+        except Exception:
+            test_name = "unknown"
+
+    if not quiet:
+        print("mozcrash checking %s for minidumps..." % dump_directory)
+
+    crash_info = CrashInfo(
+        dump_directory,
+        symbols_path,
+        dump_save_path=dump_save_path,
+        stackwalk_binary=stackwalk_binary,
+        keep=keep,
+    )
+
+    crash_count = 0
+    for info in crash_info:
+        crash_count += 1
+        output = None
+        if info.java_stack:
+            output = "PROCESS-CRASH | {name} | {stack}".format(
+                name=test_name, stack=info.java_stack
+            )
+        elif not quiet:
+            stackwalk_output = ["Crash dump filename: {}".format(info.minidump_path)]
+            if info.reason:
+                stackwalk_output.append("Mozilla crash reason: %s" % info.reason)
+            if info.stackwalk_stderr:
+                stackwalk_output.append("stderr from minidump-stackwalk:")
+                stackwalk_output.append(info.stackwalk_stderr)
+            elif info.stackwalk_stdout is not None:
+                stackwalk_output.append(info.stackwalk_stdout)
+            if info.stackwalk_retcode is not None and info.stackwalk_retcode != 0:
+                stackwalk_output.append(
+                    "minidump-stackwalk exited with return code {}".format(
+                        info.stackwalk_retcode
+                    )
+                )
+            signature = info.signature if info.signature else "unknown top frame"
+
+            output = "PROCESS-CRASH | {name} | application crashed [{sig}]\n{out}\n{err}".format(
+                name=test_name,
+                sig=signature,
+                out="\n".join(stackwalk_output),
+                err="\n".join(info.stackwalk_errors),
+            )
+        if output is not None:
+            if six.PY2 and sys.stdout.encoding != "UTF-8":
+                output = output.encode("utf-8")
+            print(output)
+
+    return crash_count
+
+
+def log_crashes(
+    logger,
+    dump_directory,
+    symbols_path,
+    process=None,
+    test=None,
+    stackwalk_binary=None,
+    dump_save_path=None,
+    quiet=False,
+):
+    """Log crashes using a structured logger"""
+    crash_count = 0
+    for info in CrashInfo(
+        dump_directory,
+        symbols_path,
+        dump_save_path=dump_save_path,
+        stackwalk_binary=stackwalk_binary,
+    ):
+        crash_count += 1
+        if not quiet:
+            kwargs = info._asdict()
+            kwargs.pop("extra")
+            logger.crash(process=process, test=test, **kwargs)
+    return crash_count
+
+
+# Function signatures of abort functions which should be ignored when
+# determining the appropriate frame for the crash signature.
+ABORT_SIGNATURES = (
+    "Abort(char const*)",
+    "RustMozCrash",
+    "NS_DebugBreak",
+    # This signature is part of Rust panic stacks on some platforms. On
+    # others, it includes a template parameter containing "core::panic::" and
+    # is automatically filtered out by that pattern.
+    "core::ops::function::Fn::call",
+    "gkrust_shared::panic_hook",
+    "mozglue_static::panic_hook",
+    "intentional_panic",
+    "mozalloc_abort",
+    "mozalloc_abort(char const* const)",
+    "static void Abort(const char *)",
+    "std::sys_common::backtrace::__rust_end_short_backtrace",
+    "rust_begin_unwind",
+    # This started showing up when we enabled dumping inlined functions
+    "MOZ_Crash",
+)
+
+# Similar to above, but matches if the substring appears anywhere in the
+# frame's signature.
+ABORT_SUBSTRINGS = (
+    # On some platforms, Rust panic frames unfortunately appear without the
+    # std::panicking or core::panic namespaces.
+    "_panic_",
+    "core::panic::",
+    "core::panicking::",
+    "core::result::unwrap_failed",
+    "std::panicking::",
+)
+
+
+class CrashInfo(object):
+    """Get information about a crash based on dump files.
+
+    Typical usage is to iterate over the CrashInfo object. This returns StackInfo
+    objects, one for each crash dump file that is found in the dump_directory.
+
+    :param dump_directory: Path to search for minidump files
+    :param symbols_path: Path to a path to a directory containing symbols to use for
+                         dump processing. This can either be a path to a directory
+                         containing Breakpad-format symbols, or a URL to a zip file
+                         containing a set of symbols.
+    :param dump_save_path: Path to which to save the dump files. If this is None,
+                           the MINIDUMP_SAVE_PATH environment variable will be used.
+    :param stackwalk_binary: Path to the minidump-stackwalk binary. If this is None,
+                             the MINIDUMP_STACKWALK environment variable will be used
+                             as the path to the minidump binary. If neither is set,
+                             then ~/.mozbuild/minidump-stackwalk/minidump-stackwalk
+                             will be used."""
+
+    def __init__(
+        self,
+        dump_directory,
+        symbols_path,
+        dump_save_path=None,
+        stackwalk_binary=None,
+        keep=False,
+    ):
+        self.dump_directory = dump_directory
+        self.symbols_path = symbols_path
+        self.remove_symbols = False
+        self.brief_output = False
+        self.keep = keep
+
+        if dump_save_path is None:
+            dump_save_path = os.environ.get("MINIDUMP_SAVE_PATH", None)
+        self.dump_save_path = dump_save_path
+
+        if stackwalk_binary is None:
+            stackwalk_binary = os.environ.get("MINIDUMP_STACKWALK", None)
+        if stackwalk_binary is None:
+            # Location of minidump-stackwalk installed by "mach bootstrap".
+            #
+            # In the transition to rust-minidump, the binary name was changed
+            # from minidump_stackwalk to minidump-stackwalk, but if the user
+            # hasn't run mach bootstrap yet, then they'll still have the old
+            # binary. So we try both names (but prefer the new one).
+            #
+            # If neither exists, then we intentionally leave a junk path
+            # in stackwalk_binary, as later checks will handle this properly
+            # when our actual error reporting is setup.
+            possible_names = ["minidump-stackwalk", "minidump_stackwalk"]
+            state_dir = os.environ.get(
+                "MOZBUILD_STATE_PATH",
+                os.path.expanduser(os.path.join("~", ".mozbuild")),
+            )
+            for possible_name in possible_names:
+                stackwalk_binary = os.path.join(state_dir, possible_name, possible_name)
+                if mozinfo.isWin and not stackwalk_binary.endswith(".exe"):
+                    stackwalk_binary += ".exe"
+                if os.path.exists(stackwalk_binary):
+                    # If we reach this point, then we're almost certainly
+                    # running on a local user's machine. Full minidump-stackwalk
+                    # output is a bit noisy and verbose for that use-case,
+                    # so we should use the --brief output.
+                    self.brief_output = True
+                    break
+
+        self.stackwalk_binary = stackwalk_binary
+
+        self.logger = get_logger()
+        self._dump_files = None
+
+    @retriable(attempts=5, sleeptime=5, sleepscale=2)
+    def _get_symbols(self):
+        if not self.symbols_path:
+            self.logger.warning(
+                "No local symbols_path provided, only http symbols will be used."
+            )
+
+        # This updates self.symbols_path so we only download once.
+        if mozfile.is_url(self.symbols_path):
+            self.remove_symbols = True
+            self.logger.info("Downloading symbols from: %s" % self.symbols_path)
+            # Get the symbols and write them to a temporary zipfile
+            data = six.moves.urllib.request.urlopen(self.symbols_path)
+            with tempfile.TemporaryFile() as symbols_file:
+                symbols_file.write(data.read())
+                # extract symbols to a temporary directory (which we'll delete after
+                # processing all crashes)
+                self.symbols_path = tempfile.mkdtemp()
+                with zipfile.ZipFile(symbols_file, "r") as zfile:
+                    mozfile.extract_zip(zfile, self.symbols_path)
+
+    @property
+    def dump_files(self):
+        """List of tuple (path_to_dump_file, path_to_extra_file) for each dump
+        file in self.dump_directory. The extra files may not exist."""
+        if self._dump_files is None:
+            self._dump_files = [
+                (path, os.path.splitext(path)[0] + ".extra")
+                for path in reversed(
+                    sorted(glob.glob(os.path.join(self.dump_directory, "*.dmp")))
+                )
+            ]
+            max_dumps = 10
+            if len(self._dump_files) > max_dumps:
+                self.logger.warning(
+                    "Found %d dump files -- limited to %d!"
+                    % (len(self._dump_files), max_dumps)
+                )
+                del self._dump_files[max_dumps:]
+
+        return self._dump_files
+
+    @property
+    def has_dumps(self):
+        """Boolean indicating whether any crash dump files were found in the
+        current directory"""
+        return len(self.dump_files) > 0
+
+    def __iter__(self):
+        for path, extra in self.dump_files:
+            rv = self._process_dump_file(path, extra)
+            yield rv
+
+        if self.remove_symbols:
+            mozfile.remove(self.symbols_path)
+
+    def _process_dump_file(self, path, extra):
+        """Process a single dump file using self.stackwalk_binary, and return a
+        tuple containing properties of the crash dump.
+
+        :param path: Path to the minidump file to analyse
+        :return: A StackInfo tuple with the fields::
+                   minidump_path: Path of the dump file
+                   signature: The top frame of the stack trace, or None if it
+                              could not be determined.
+                   stackwalk_stdout: String of stdout data from stackwalk
+                   stackwalk_stderr: String of stderr data from stackwalk or
+                                     None if it succeeded
+                   stackwalk_retcode: Return code from stackwalk
+                   stackwalk_errors: List of errors in human-readable form that prevented
+                                     stackwalk being launched.
+        """
+        self._get_symbols()
+
+        errors = []
+        signature = None
+        include_stderr = False
+        out = None
+        err = None
+        retcode = None
+        reason = None
+        java_stack = None
+        if (
+            self.stackwalk_binary
+            and os.path.exists(self.stackwalk_binary)
+            and os.access(self.stackwalk_binary, os.X_OK)
+        ):
+            # If minidump-stackwalk -V fails, then we're using the old breakpad version,
+            # (minidump_stackwalk) which is implicitly "human" output and doesn't
+            # support the --human flag.
+            #
+            # Otherwise we're using rust-minidump's minidump-stackwalk. Before 0.9.6
+            # --human had to be passed explicitly to get human output, but now it's
+            # the default (to behave more similarly to breakpad). But since we've
+            # already filtered out breakpad as an option, we can explicitly pass
+            # --human.
+            #
+            # In the future we would also like to use rust-minidump's --cyborg
+            # (introduced in 0.9.5), which outputs both human-readable *and*
+            # machine-readable (JSON) output, so we can output something nice to the
+            # CLI, but more reliably parse all the details we care about.
+            # The machine-readable output is also exactly what socorro (crash-stats)
+            # consumes, so in theory using it will make the two more compatible.
+            stackwalk_version_check = subprocess.Popen(
+                [self.stackwalk_binary, "-V"],
+                stdout=subprocess.DEVNULL,
+                stderr=subprocess.DEVNULL,
+            )
+            stackwalk_version_check.wait()
+
+            # Right now we don't have any rust-minidump-version-specific handling,
+            # so we don't need to bother parsing the output at all. But when we
+            # want to start using newer features (like --cyborg) we should parse
+            # the version string, so here's some notes on that:
+            #
+            # Example outputs:
+            # minidump_stackwalk 0.9.2
+            # minidump-stackwalk 0.9.5
+            #
+            # Either `_` or `-` may be used in the name, so be careful of that
+            # (newer versions should use `-`). Otherwise the actual version number
+            # is the usual `<major>.<minor>.<patch>` that can be parsed with
+            # `looseversion.LooseVersion`.
+            rust_minidump = stackwalk_version_check.returncode == 0
+
+            # Now build up the actual command
+            command = [self.stackwalk_binary]
+
+            # Fallback to the symbols server for unknown symbols on automation
+            # (mostly for system libraries).
+            if "MOZ_AUTOMATION" in os.environ:
+                command.append("--symbols-url=https://symbols.mozilla.org/")
+
+            # Specify the kind of output
+            if rust_minidump:
+                command.append("--human")
+                if self.brief_output:
+                    command.append("--brief")
+
+            # The minidump path and symbols_path values are positional and come last
+            # (in practice the CLI parsers are more permissive, but best not to
+            # unecessarily play with fire).
+            command.append(path)
+
+            if self.symbols_path:
+                command.append(self.symbols_path)
+
+            self.logger.info("Copy/paste: {}".format(" ".join(command)))
+            # run minidump-stackwalk
+            p = subprocess.Popen(
+                command, stdout=subprocess.PIPE, stderr=subprocess.PIPE
+            )
+            (out, err) = p.communicate()
+            retcode = p.returncode
+            if six.PY3:
+                out = six.ensure_str(out)
+                err = six.ensure_str(err)
+
+            if len(out) > 3:
+                # minidump-stackwalk is chatty,
+                # so ignore stderr when it succeeds.
+                # The top frame of the crash is always the line after "Thread N (crashed)"
+                # Examples:
+                #  0  libc.so + 0xa888
+                #  0  libnss3.so!nssCertificate_Destroy [certificate.c : 102 + 0x0]
+                #  0  mozjs.dll!js::GlobalObject::getDebuggers() [GlobalObject.cpp:89df18f9b6da : 580 + 0x0] # noqa
+                # 0  libxul.so!void js::gc::MarkInternal<JSObject>(JSTracer*, JSObject**)
+                # [Marking.cpp : 92 + 0x28]
+                lines = out.splitlines()
+                for i, line in enumerate(lines):
+                    if "(crashed)" in line:
+                        # Try to find the first frame that isn't an abort
+                        # function to use as the signature.
+                        for line in lines[i + 1 :]:
+                            if not line.startswith(" "):
+                                break
+
+                            match = re.search(r"^ \d  (?:.*!)?(?:void )?([^\[]+)", line)
+                            if match:
+                                func = match.group(1).strip()
+                                signature = "@ %s" % func
+
+                                if not (
+                                    func in ABORT_SIGNATURES
+                                    or any(pat in func for pat in ABORT_SUBSTRINGS)
+                                ):
+                                    break
+                        break
+            else:
+                include_stderr = True
+
+        else:
+            if not self.stackwalk_binary:
+                errors.append(
+                    "MINIDUMP_STACKWALK not set, can't process dump. Either set "
+                    "MINIDUMP_STACKWALK or use mach bootstrap --no-system-changes "
+                    "to install minidump-stackwalk."
+                )
+            elif self.stackwalk_binary and not os.path.exists(self.stackwalk_binary):
+                errors.append(
+                    "MINIDUMP_STACKWALK binary not found: %s. Use mach bootstrap "
+                    "--no-system-changes to install minidump-stackwalk."
+                    % self.stackwalk_binary
+                )
+            elif not os.access(self.stackwalk_binary, os.X_OK):
+                errors.append("This user cannot execute the MINIDUMP_STACKWALK binary.")
+
+        if os.path.exists(extra):
+            crash_dict = self._parse_extra_file(extra)
+            reason = crash_dict.get("MozCrashReason")
+            java_stack = crash_dict.get("JavaStackTrace")
+
+        if self.dump_save_path:
+            self._save_dump_file(path, extra)
+
+        if os.path.exists(path) and not self.keep:
+            mozfile.remove(path)
+        if os.path.exists(extra) and not self.keep:
+            mozfile.remove(extra)
+
+        return StackInfo(
+            path,
+            signature,
+            out,
+            err if include_stderr else None,
+            retcode,
+            errors,
+            extra,
+            reason,
+            java_stack,
+        )
+
+    def _parse_extra_file(self, path):
+        with open(path) as file:
+            try:
+                return json.load(file)
+            except ValueError:
+                self.logger.warning(".extra file does not contain proper json")
+                return {}
+
+    def _save_dump_file(self, path, extra):
+        if os.path.isfile(self.dump_save_path):
+            os.unlink(self.dump_save_path)
+        if not os.path.isdir(self.dump_save_path):
+            try:
+                os.makedirs(self.dump_save_path)
+            except OSError:
+                pass
+
+        shutil.move(path, self.dump_save_path)
+        self.logger.info(
+            "Saved minidump as {}".format(
+                os.path.join(self.dump_save_path, os.path.basename(path))
+            )
+        )
+
+        if os.path.isfile(extra):
+            shutil.move(extra, self.dump_save_path)
+            self.logger.info(
+                "Saved app info as {}".format(
+                    os.path.join(self.dump_save_path, os.path.basename(extra))
+                )
+            )
+
+
+def check_for_java_exception(logcat, test_name=None, quiet=False):
+    """
+    Print a summary of a fatal Java exception, if present in the provided
+    logcat output.
+
+    Today, exceptions in geckoview are usually noted in the minidump .extra file, allowing
+    java exceptions to be reported by the "normal" minidump processing, like log_crashes();
+    therefore, this function may be extraneous (but maintained for now, while exception
+    handling is evolving).
+
+    Example:
+    PROCESS-CRASH | <test-name> | java-exception java.lang.NullPointerException at org.mozilla.gecko.GeckoApp$21.run(GeckoApp.java:1833) # noqa
+
+    `logcat` should be a list of strings.
+
+    If `test_name` is set it will be used as the test name in log output. If not set the
+    filename of the calling function will be used.
+
+    If `quiet` is set, no PROCESS-CRASH message will be printed to stdout if a
+    crash is detected.
+
+    Returns True if a fatal Java exception was found, False otherwise.
+    """
+
+    # try to get the caller's filename if no test name is given
+    if test_name is None:
+        try:
+            test_name = os.path.basename(sys._getframe(1).f_code.co_filename)
+        except Exception:
+            test_name = "unknown"
+
+    found_exception = False
+
+    for i, line in enumerate(logcat):
+        # Logs will be of form:
+        #
+        # 01-30 20:15:41.937 E/GeckoAppShell( 1703): >>> REPORTING UNCAUGHT EXCEPTION FROM THREAD 9 ("GeckoBackgroundThread") # noqa
+        # 01-30 20:15:41.937 E/GeckoAppShell( 1703): java.lang.NullPointerException
+        # 01-30 20:15:41.937 E/GeckoAppShell( 1703): at org.mozilla.gecko.GeckoApp$21.run(GeckoApp.java:1833) # noqa
+        # 01-30 20:15:41.937 E/GeckoAppShell( 1703): at android.os.Handler.handleCallback(Handler.java:587) # noqa
+        if "REPORTING UNCAUGHT EXCEPTION" in line:
+            # Strip away the date, time, logcat tag and pid from the next two lines and
+            # concatenate the remainder to form a concise summary of the exception.
+            found_exception = True
+            if len(logcat) >= i + 3:
+                logre = re.compile(r".*\): \t?(.*)")
+                m = logre.search(logcat[i + 1])
+                if m and m.group(1):
+                    exception_type = m.group(1)
+                m = logre.search(logcat[i + 2])
+                if m and m.group(1):
+                    exception_location = m.group(1)
+                if not quiet:
+                    output = (
+                        "PROCESS-CRASH | {name} | java-exception {type} {loc}".format(
+                            name=test_name, type=exception_type, loc=exception_location
+                        )
+                    )
+                    print(output.encode("utf-8"))
+            else:
+                print(
+                    "Automation Error: java exception in logcat at line "
+                    "{0} of {1}: {2}".format(i, len(logcat), line)
+                )
+            break
+
+    return found_exception
+
+
+if mozinfo.isWin:
+    import ctypes
+    import uuid
+
+    kernel32 = ctypes.windll.kernel32
+    OpenProcess = kernel32.OpenProcess
+    CloseHandle = kernel32.CloseHandle
+
+    def write_minidump(pid, dump_directory, utility_path):
+        """
+        Write a minidump for a process.
+
+        :param pid: PID of the process to write a minidump for.
+        :param dump_directory: Directory in which to write the minidump.
+        """
+        PROCESS_QUERY_INFORMATION = 0x0400
+        PROCESS_VM_READ = 0x0010
+        GENERIC_READ = 0x80000000
+        GENERIC_WRITE = 0x40000000
+        CREATE_ALWAYS = 2
+        FILE_ATTRIBUTE_NORMAL = 0x80
+        INVALID_HANDLE_VALUE = -1
+
+        log = get_logger()
+        file_name = os.path.join(dump_directory, str(uuid.uuid4()) + ".dmp")
+
+        if not os.path.exists(dump_directory):
+            # `kernal32.CreateFileW` can fail to create the dmp file if the dump
+            # directory was deleted or doesn't exist (error code 3).
+            os.makedirs(dump_directory)
+
+        if mozinfo.info["bits"] != ctypes.sizeof(ctypes.c_voidp) * 8 and utility_path:
+            # We're not going to be able to write a minidump with ctypes if our
+            # python process was compiled for a different architecture than
+            # firefox, so we invoke the minidumpwriter utility program.
+
+            minidumpwriter = os.path.normpath(
+                os.path.join(utility_path, "minidumpwriter.exe")
+            )
+            log.info(
+                "Using {} to write a dump to {} for [{}]".format(
+                    minidumpwriter, file_name, pid
+                )
+            )
+            if not os.path.exists(minidumpwriter):
+                log.error("minidumpwriter not found in {}".format(utility_path))
+                return
+
+            status = subprocess.Popen([minidumpwriter, str(pid), file_name]).wait()
+            if status:
+                log.error("minidumpwriter exited with status: %d" % status)
+            return
+
+        log.info("Writing a dump to {} for [{}]".format(file_name, pid))
+
+        proc_handle = OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, 0, pid)
+        if not proc_handle:
+            err = kernel32.GetLastError()
+            log.warning("unable to get handle for pid %d: %d" % (pid, err))
+            return
+
+        if not isinstance(file_name, six.text_type):
+            # Convert to unicode explicitly so our path will be valid as input
+            # to CreateFileW
+            file_name = six.text_type(file_name, sys.getfilesystemencoding())
+
+        file_handle = kernel32.CreateFileW(
+            file_name,
+            GENERIC_READ | GENERIC_WRITE,
+            0,
+            None,
+            CREATE_ALWAYS,
+            FILE_ATTRIBUTE_NORMAL,
+            None,
+        )
+        if file_handle != INVALID_HANDLE_VALUE:
+            if not ctypes.windll.dbghelp.MiniDumpWriteDump(
+                proc_handle,
+                pid,
+                file_handle,
+                # Dump type - MiniDumpNormal
+                0,
+                # Exception parameter
+                None,
+                # User stream parameter
+                None,
+                # Callback parameter
+                None,
+            ):
+                err = kernel32.GetLastError()
+                log.warning("unable to dump minidump file for pid %d: %d" % (pid, err))
+            CloseHandle(file_handle)
+        else:
+            err = kernel32.GetLastError()
+            log.warning("unable to create minidump file for pid %d: %d" % (pid, err))
+        CloseHandle(proc_handle)
+
+    def kill_pid(pid):
+        """
+        Terminate a process with extreme prejudice.
+
+        :param pid: PID of the process to terminate.
+        """
+        PROCESS_TERMINATE = 0x0001
+        SYNCHRONIZE = 0x00100000
+        WAIT_OBJECT_0 = 0x0
+        WAIT_FAILED = -1
+        logger = get_logger()
+        handle = OpenProcess(PROCESS_TERMINATE | SYNCHRONIZE, 0, pid)
+        if handle:
+            if kernel32.TerminateProcess(handle, 1):
+                # TerminateProcess is async; wait up to 30 seconds for process to
+                # actually terminate, then give up so that clients are not kept
+                # waiting indefinitely for hung processes.
+                status = kernel32.WaitForSingleObject(handle, 30000)
+                if status == WAIT_FAILED:
+                    err = kernel32.GetLastError()
+                    logger.warning(
+                        "kill_pid(): wait failed (%d) terminating pid %d: error %d"
+                        % (status, pid, err)
+                    )
+                elif status != WAIT_OBJECT_0:
+                    logger.warning(
+                        "kill_pid(): wait failed (%d) terminating pid %d"
+                        % (status, pid)
+                    )
+            else:
+                err = kernel32.GetLastError()
+                logger.warning(
+                    "kill_pid(): unable to terminate pid %d: %d" % (pid, err)
+                )
+            CloseHandle(handle)
+        else:
+            err = kernel32.GetLastError()
+            logger.warning(
+                "kill_pid(): unable to get handle for pid %d: %d" % (pid, err)
+            )
+
+
+else:
+
+    def kill_pid(pid):
+        """
+        Terminate a process with extreme prejudice.
+
+        :param pid: PID of the process to terminate.
+        """
+        os.kill(pid, signal.SIGKILL)
+
+
+def kill_and_get_minidump(pid, dump_directory, utility_path=None):
+    """
+    Attempt to kill a process and leave behind a minidump describing its
+    execution state.
+
+    :param pid: The PID of the process to kill.
+    :param dump_directory: The directory where a minidump should be written on
+    Windows, where the dump will be written from outside the process.
+
+    On Windows a dump will be written using the MiniDumpWriteDump function
+    from DbgHelp.dll. On Linux and OS X the process will be sent a SIGABRT
+    signal to trigger minidump writing via a Breakpad signal handler. On other
+    platforms the process will simply be killed via SIGKILL.
+
+    If the process is hung in such a way that it cannot respond to SIGABRT
+    it may still be running after this function returns. In that case it
+    is the caller's responsibility to deal with killing it.
+    """
+    needs_killing = True
+    if mozinfo.isWin:
+        write_minidump(pid, dump_directory, utility_path)
+    elif mozinfo.isLinux or mozinfo.isMac:
+        os.kill(pid, signal.SIGABRT)
+        needs_killing = False
+    if needs_killing:
+        kill_pid(pid)
+
+
+def cleanup_pending_crash_reports():
+    """
+    Delete any pending crash reports.
+
+    The presence of pending crash reports may be reported by the browser,
+    affecting test results; it is best to ensure that these are removed
+    before starting any browser tests.
+
+    Firefox stores pending crash reports in "<UAppData>/Crash Reports".
+    If the browser is not running, it cannot provide <UAppData>, so this
+    code tries to anticipate its value.
+
+    See dom/system/OSFileConstants.cpp for platform variations of <UAppData>.
+    """
+    if mozinfo.isWin:
+        location = os.path.expanduser(
+            "~\\AppData\\Roaming\\Mozilla\\Firefox\\Crash Reports"
+        )
+    elif mozinfo.isMac:
+        location = os.path.expanduser(
+            "~/Library/Application Support/firefox/Crash Reports"
+        )
+    else:
+        location = os.path.expanduser("~/.mozilla/firefox/Crash Reports")
+    logger = get_logger()
+    if os.path.exists(location):
+        try:
+            mozfile.remove(location)
+            logger.info("Removed pending crash reports at '%s'" % location)
+        except Exception:
+            pass
+
+
+if __name__ == "__main__":
+    import argparse
+
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--stackwalk-binary", "-b")
+    parser.add_argument("--dump-save-path", "-o")
+    parser.add_argument("--test-name", "-n")
+    parser.add_argument("--keep", action="store_true")
+    parser.add_argument("dump_directory")
+    parser.add_argument("symbols_path")
+    args = parser.parse_args()
+
+    check_for_crashes(
+        args.dump_directory,
+        args.symbols_path,
+        stackwalk_binary=args.stackwalk_binary,
+        dump_save_path=args.dump_save_path,
+        test_name=args.test_name,
+        keep=args.keep,
+    )
diff --git a/testing/mozbase/mozcrash/setup.cfg b/testing/mozbase/mozcrash/setup.cfg
new file mode 100644
index 0000000000..3c6e79cf31
--- /dev/null
+++ b/testing/mozbase/mozcrash/setup.cfg
@@ -0,0 +1,2 @@
+[bdist_wheel]
+universal=1
diff --git a/testing/mozbase/mozcrash/setup.py b/testing/mozbase/mozcrash/setup.py
new file mode 100644
index 0000000000..d67060149b
--- /dev/null
+++ b/testing/mozbase/mozcrash/setup.py
@@ -0,0 +1,33 @@
+# 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 setuptools import setup
+
+PACKAGE_NAME = "mozcrash"
+PACKAGE_VERSION = "2.2.0"
+
+# dependencies
+deps = ["mozfile >= 1.0", "mozlog >= 6.0"]
+
+setup(
+    name=PACKAGE_NAME,
+    version=PACKAGE_VERSION,
+    description="Library for printing stack traces from minidumps "
+    "left behind by crashed processes",
+    long_description="see https://firefox-source-docs.mozilla.org/mozbase/index.html",
+    classifiers=[
+        "Programming Language :: Python :: 2.7",
+        "Programming Language :: Python :: 3.5",
+    ],
+    # Get strings from http://pypi.python.org/pypi?%3Aaction=list_classifiers
+    keywords="mozilla",
+    author="Mozilla Automation and Tools team",
+    author_email="tools@lists.mozilla.org",
+    url="https://wiki.mozilla.org/Auto-tools/Projects/Mozbase",
+    license="MPL",
+    packages=["mozcrash"],
+    include_package_data=True,
+    zip_safe=False,
+    install_requires=deps,
+)
diff --git a/testing/mozbase/mozcrash/tests/conftest.py b/testing/mozbase/mozcrash/tests/conftest.py
new file mode 100644
index 0000000000..4827515723
--- /dev/null
+++ b/testing/mozbase/mozcrash/tests/conftest.py
@@ -0,0 +1,127 @@
+# coding=UTF-8
+
+import uuid
+
+import mozcrash
+import pytest
+from py._path.common import fspath
+
+
+@pytest.fixture(scope="session")
+def stackwalk(tmpdir_factory):
+    stackwalk = tmpdir_factory.mktemp("stackwalk_binary").join("stackwalk")
+    stackwalk.write("fake binary")
+    stackwalk.chmod(0o744)
+    return stackwalk
+
+
+@pytest.fixture
+def check_for_crashes(tmpdir, stackwalk, monkeypatch):
+    monkeypatch.delenv("MINIDUMP_SAVE_PATH", raising=False)
+
+    def wrapper(
+        dump_directory=fspath(tmpdir),
+        symbols_path="symbols_path",
+        stackwalk_binary=fspath(stackwalk),
+        dump_save_path=None,
+        test_name=None,
+        quiet=True,
+    ):
+        return mozcrash.check_for_crashes(
+            dump_directory,
+            symbols_path,
+            stackwalk_binary,
+            dump_save_path,
+            test_name,
+            quiet,
+        )
+
+    return wrapper
+
+
+@pytest.fixture
+def check_for_java_exception():
+    def wrapper(logcat=None, test_name=None, quiet=True):
+        return mozcrash.check_for_java_exception(logcat, test_name, quiet)
+
+    return wrapper
+
+
+def minidump_files(request, tmpdir):
+    files = []
+
+    for i in range(getattr(request, "param", 1)):
+        name = uuid.uuid4()
+
+        dmp = tmpdir.join("{}.dmp".format(name))
+        dmp.write("foo")
+
+        extra = tmpdir.join("{}.extra".format(name))
+
+        extra.write_text(
+            u"""
+{
+  "ContentSandboxLevel":"2",
+  "TelemetryEnvironment":"{🍪}",
+  "EMCheckCompatibility":"true",
+  "ProductName":"Firefox",
+  "ContentSandboxCapabilities":"119",
+  "TelemetryClientId":"",
+  "Vendor":"Mozilla",
+  "InstallTime":"1000000000",
+  "Theme":"classic/1.0",
+  "ReleaseChannel":"default",
+  "ServerURL":"https://crash-reports.mozilla.com",
+  "SafeMode":"0",
+  "ContentSandboxCapable":"1",
+  "useragent_locale":"en-US",
+  "Version":"55.0a1",
+  "BuildID":"20170512114708",
+  "ProductID":"{ec8030f7-c20a-464f-9b0e-13a3a9e97384}",
+  "MozCrashReason": "MOZ_CRASH()",
+  "TelemetryServerURL":"",
+  "DOMIPCEnabled":"1",
+  "Add-ons":"",
+  "CrashTime":"1494582646",
+  "UptimeTS":"14.9179586",
+  "ContentSandboxEnabled":"1",
+  "ProcessType":"content",
+  "StartupTime":"1000000000",
+  "URL":"about:home"
+}
+
+        """,
+            encoding="utf-8",
+        )
+
+        files.append({"dmp": dmp, "extra": extra})
+
+    return files
+
+
+@pytest.fixture(name="minidump_files")
+def minidump_files_fixture(request, tmpdir):
+    return minidump_files(request, tmpdir)
+
+
+@pytest.fixture(autouse=True)
+def mock_popen(monkeypatch):
+    """Generate a class that can mock subprocess.Popen.
+
+    :param stdouts: Iterable that should return an iterable for the
+                    stdout of each process in turn.
+    """
+
+    class MockPopen(object):
+        def __init__(self, args, *args_rest, **kwargs):
+            # all_popens.append(self)
+            self.args = args
+            self.returncode = 0
+
+        def communicate(self):
+            return (u"Stackwalk command: {}".format(" ".join(self.args)), "")
+
+        def wait(self):
+            return self.returncode
+
+    monkeypatch.setattr(mozcrash.mozcrash.subprocess, "Popen", MockPopen)
diff --git a/testing/mozbase/mozcrash/tests/manifest.ini b/testing/mozbase/mozcrash/tests/manifest.ini
new file mode 100644
index 0000000000..5a7e75b832
--- /dev/null
+++ b/testing/mozbase/mozcrash/tests/manifest.ini
@@ -0,0 +1,7 @@
+[DEFAULT]
+subsuite = mozbase
+[test_basic.py]
+[test_java_exception.py]
+[test_save_path.py]
+[test_stackwalk.py]
+[test_symbols_path.py]
diff --git a/testing/mozbase/mozcrash/tests/test_basic.py b/testing/mozbase/mozcrash/tests/test_basic.py
new file mode 100644
index 0000000000..157a5785c1
--- /dev/null
+++ b/testing/mozbase/mozcrash/tests/test_basic.py
@@ -0,0 +1,43 @@
+#!/usr/bin/env python
+# coding=UTF-8
+
+import mozunit
+import pytest
+from conftest import fspath
+
+
+def test_no_dump_files(check_for_crashes):
+    """Test that check_for_crashes returns 0 if no dumps are present."""
+    assert 0 == check_for_crashes()
+
+
+@pytest.mark.parametrize("minidump_files", [3], indirect=True)
+def test_dump_count(check_for_crashes, minidump_files):
+    """Test that check_for_crashes returns the number of crash dumps."""
+    assert 3 == check_for_crashes()
+
+
+def test_dump_directory_unicode(request, check_for_crashes, tmpdir, capsys):
+    """Test that check_for_crashes can handle unicode in dump_directory."""
+    from conftest import minidump_files
+
+    tmpdir = tmpdir.ensure(u"🍪", dir=1)
+    minidump_files = minidump_files(request, tmpdir)
+
+    assert 1 == check_for_crashes(dump_directory=fspath(tmpdir), quiet=False)
+
+    out, _ = capsys.readouterr()
+    assert fspath(minidump_files[0]["dmp"]) in out
+    assert u"🍪" in out
+
+
+def test_test_name_unicode(check_for_crashes, minidump_files, capsys):
+    """Test that check_for_crashes can handle unicode in dump_directory."""
+    assert 1 == check_for_crashes(test_name=u"🍪", quiet=False)
+
+    out, err = capsys.readouterr()
+    assert u"| 🍪 |" in out
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/testing/mozbase/mozcrash/tests/test_java_exception.py b/testing/mozbase/mozcrash/tests/test_java_exception.py
new file mode 100644
index 0000000000..f48ce2cc3e
--- /dev/null
+++ b/testing/mozbase/mozcrash/tests/test_java_exception.py
@@ -0,0 +1,51 @@
+#!/usr/bin/env python
+# coding=UTF-8
+
+import mozunit
+import pytest
+
+
+@pytest.fixture
+def test_log():
+    return [
+        "01-30 20:15:41.937 E/GeckoAppShell( 1703): >>> "
+        'REPORTING UNCAUGHT EXCEPTION FROM THREAD 9 ("GeckoBackgroundThread")',
+        "01-30 20:15:41.937 E/GeckoAppShell( 1703): java.lang.NullPointerException",
+        "01-30 20:15:41.937 E/GeckoAppShell( 1703):"
+        "    at org.mozilla.gecko.GeckoApp$21.run(GeckoApp.java:1833)",
+        "01-30 20:15:41.937 E/GeckoAppShell( 1703):"
+        "    at android.os.Handler.handleCallback(Handler.java:587)",
+    ]
+
+
+def test_uncaught_exception(check_for_java_exception, test_log):
+    """Test for an exception which should be caught."""
+    assert 1 == check_for_java_exception(test_log)
+
+
+def test_truncated_exception(check_for_java_exception, test_log):
+    """Test for an exception which should be caught which was truncated."""
+    truncated_log = list(test_log)
+    truncated_log[0], truncated_log[1] = truncated_log[1], truncated_log[0]
+
+    assert 1 == check_for_java_exception(truncated_log)
+
+
+def test_unchecked_exception(check_for_java_exception, test_log):
+    """Test for an exception which should not be caught."""
+    passable_log = list(test_log)
+    passable_log[0] = (
+        "01-30 20:15:41.937 E/GeckoAppShell( 1703):"
+        ' >>> NOT-SO-BAD EXCEPTION FROM THREAD 9 ("GeckoBackgroundThread")'
+    )
+
+    assert 0 == check_for_java_exception(passable_log)
+
+
+def test_test_name_unicode(check_for_java_exception, test_log):
+    """Test that check_for_crashes can handle unicode in dump_directory."""
+    assert 1 == check_for_java_exception(test_log, test_name=u"🍪", quiet=False)
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/testing/mozbase/mozcrash/tests/test_save_path.py b/testing/mozbase/mozcrash/tests/test_save_path.py
new file mode 100644
index 0000000000..fad83ab71b
--- /dev/null
+++ b/testing/mozbase/mozcrash/tests/test_save_path.py
@@ -0,0 +1,68 @@
+#!/usr/bin/env python
+
+import os
+
+import mozunit
+import pytest
+from conftest import fspath
+
+
+def test_save_path_not_present(check_for_crashes, minidump_files, tmpdir):
+    """Test that dump_save_path works when the directory doesn't exist."""
+    save_path = tmpdir.join("saved")
+
+    assert 1 == check_for_crashes(dump_save_path=fspath(save_path))
+
+    assert save_path.join(minidump_files[0]["dmp"].basename).check()
+    assert save_path.join(minidump_files[0]["extra"].basename).check()
+
+
+def test_save_path(check_for_crashes, minidump_files, tmpdir):
+    """Test that dump_save_path works."""
+    save_path = tmpdir.mkdir("saved")
+
+    assert 1 == check_for_crashes(dump_save_path=fspath(save_path))
+
+    assert save_path.join(minidump_files[0]["dmp"].basename).check()
+    assert save_path.join(minidump_files[0]["extra"].basename).check()
+
+
+def test_save_path_isfile(check_for_crashes, minidump_files, tmpdir):
+    """Test that dump_save_path works when the path is a file and not a directory."""
+    save_path = tmpdir.join("saved")
+    save_path.write("junk")
+
+    assert 1 == check_for_crashes(dump_save_path=fspath(save_path))
+
+    assert save_path.join(minidump_files[0]["dmp"].basename).check()
+    assert save_path.join(minidump_files[0]["extra"].basename).check()
+
+
+def test_save_path_envvar(check_for_crashes, minidump_files, tmpdir):
+    """Test that the MINDUMP_SAVE_PATH environment variable works."""
+    save_path = tmpdir.mkdir("saved")
+
+    os.environ["MINIDUMP_SAVE_PATH"] = fspath(save_path)
+    try:
+        assert 1 == check_for_crashes(dump_save_path=None)
+    finally:
+        del os.environ["MINIDUMP_SAVE_PATH"]
+
+    assert save_path.join(minidump_files[0]["dmp"].basename).check()
+    assert save_path.join(minidump_files[0]["extra"].basename).check()
+
+
+@pytest.mark.parametrize("minidump_files", [3], indirect=True)
+def test_save_multiple(check_for_crashes, minidump_files, tmpdir):
+    """Test that all minidumps are saved."""
+    save_path = tmpdir.mkdir("saved")
+
+    assert 3 == check_for_crashes(dump_save_path=fspath(save_path))
+
+    for i in range(3):
+        assert save_path.join(minidump_files[i]["dmp"].basename).check()
+        assert save_path.join(minidump_files[i]["extra"].basename).check()
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/testing/mozbase/mozcrash/tests/test_stackwalk.py b/testing/mozbase/mozcrash/tests/test_stackwalk.py
new file mode 100644
index 0000000000..7be2d82c10
--- /dev/null
+++ b/testing/mozbase/mozcrash/tests/test_stackwalk.py
@@ -0,0 +1,42 @@
+#!/usr/bin/env python
+# coding=UTF-8
+
+import os
+
+import mozunit
+from conftest import fspath
+
+
+def test_stackwalk_not_found(check_for_crashes, minidump_files, tmpdir, capsys):
+    """Test that check_for_crashes can handle unicode in dump_directory."""
+    stackwalk = tmpdir.join("stackwalk")
+
+    assert 1 == check_for_crashes(stackwalk_binary=fspath(stackwalk), quiet=False)
+
+    out, _ = capsys.readouterr()
+    assert "MINIDUMP_STACKWALK binary not found" in out
+
+
+def test_stackwalk_envvar(check_for_crashes, minidump_files, stackwalk):
+    """Test that check_for_crashes uses the MINIDUMP_STACKWALK environment var."""
+    os.environ["MINIDUMP_STACKWALK"] = fspath(stackwalk)
+    try:
+        assert 1 == check_for_crashes(stackwalk_binary=None)
+    finally:
+        del os.environ["MINIDUMP_STACKWALK"]
+
+
+def test_stackwalk_unicode(check_for_crashes, minidump_files, tmpdir, capsys):
+    """Test that check_for_crashes can handle unicode in dump_directory."""
+    stackwalk = tmpdir.mkdir(u"🍪").join("stackwalk")
+    stackwalk.write("fake binary")
+    stackwalk.chmod(0o744)
+
+    assert 1 == check_for_crashes(stackwalk_binary=fspath(stackwalk), quiet=False)
+
+    out, err = capsys.readouterr()
+    assert fspath(stackwalk) in out
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/testing/mozbase/mozcrash/tests/test_symbols_path.py b/testing/mozbase/mozcrash/tests/test_symbols_path.py
new file mode 100644
index 0000000000..9aa281bd31
--- /dev/null
+++ b/testing/mozbase/mozcrash/tests/test_symbols_path.py
@@ -0,0 +1,97 @@
+#!/usr/bin/env python
+# coding=UTF-8
+
+import zipfile
+
+import mozhttpd
+import mozunit
+from conftest import fspath
+from six import BytesIO
+from six.moves.urllib.parse import urlunsplit
+
+
+def test_symbols_path_not_present(check_for_crashes, minidump_files):
+    """Test that no symbols path let mozcrash try to find the symbols."""
+    assert 1 == check_for_crashes(symbols_path=None)
+
+
+def test_symbols_path_unicode(check_for_crashes, minidump_files, tmpdir, capsys):
+    """Test that check_for_crashes can handle unicode in dump_directory."""
+    symbols_path = tmpdir.mkdir(u"🍪")
+
+    assert 1 == check_for_crashes(symbols_path=fspath(symbols_path), quiet=False)
+
+    out, _ = capsys.readouterr()
+    assert fspath(symbols_path) in out
+
+
+def test_symbols_path_url(check_for_crashes, minidump_files):
+    """Test that passing a URL as symbols_path correctly fetches the URL."""
+    data = {"retrieved": False}
+
+    def make_zipfile():
+        zdata = BytesIO()
+        z = zipfile.ZipFile(zdata, "w")
+        z.writestr("symbols.txt", "abc/xyz")
+        z.close()
+        return zdata.getvalue()
+
+    def get_symbols(req):
+        data["retrieved"] = True
+
+        headers = {}
+        return (200, headers, make_zipfile())
+
+    httpd = mozhttpd.MozHttpd(
+        port=0,
+        urlhandlers=[{"method": "GET", "path": "/symbols", "function": get_symbols}],
+    )
+    httpd.start()
+    symbol_url = urlunsplit(
+        ("http", "%s:%d" % httpd.httpd.server_address, "/symbols", "", "")
+    )
+
+    assert 1 == check_for_crashes(symbols_path=symbol_url)
+    assert data["retrieved"]
+
+
+def test_symbols_retry(check_for_crashes, minidump_files):
+    """Test that passing a URL as symbols_path succeeds on retry after temporary HTTP failure."""
+    data = {"retrieved": False}
+    get_symbols_calls = 0
+
+    def make_zipfile():
+        zdata = BytesIO()
+        z = zipfile.ZipFile(zdata, "w")
+        z.writestr("symbols.txt", "abc/xyz")
+        z.close()
+        return zdata.getvalue()
+
+    def get_symbols(req):
+        nonlocal get_symbols_calls
+        data["retrieved"] = True
+        if get_symbols_calls > 0:
+            ret = 200
+        else:
+            ret = 504
+        get_symbols_calls += 1
+
+        headers = {}
+        return (ret, headers, make_zipfile())
+
+    httpd = mozhttpd.MozHttpd(
+        port=0,
+        urlhandlers=[{"method": "GET", "path": "/symbols", "function": get_symbols}],
+    )
+    httpd.start()
+    symbol_url = urlunsplit(
+        ("http", "%s:%d" % httpd.httpd.server_address, "/symbols", "", "")
+    )
+
+    assert 1 == check_for_crashes(symbols_path=symbol_url)
+    assert data["retrieved"]
+    assert 2 == get_symbols_calls
+
+
+if __name__ == "__main__":
+    mozunit.main()