Merging upstream version 0.1.44.

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

26 files changed, 815 insertions, 224 deletions

diff --git a/src/debputy/builtin_manifest_rules.py b/src/debputy/builtin_manifest_rules.py
index c8e6557..e420cda 100644
--- a/src/debputy/builtin_manifest_rules.py
+++ b/src/debputy/builtin_manifest_rules.py
@@ -226,10 +226,7 @@ def builtin_mode_normalization_rules(
                 path_type=PathType.FILE,
                 recursive_match=True,
             ),
-            SymbolicMode.parse_filesystem_mode(
-                "a-x",
-                attribute_path['"*.pm'],
-            ),
+            _STD_FILE_MODE,
         )
         for perl_dir in perl_module_dirs(dpkg_architecture_variables, dctrl_bin)
     )
@@ -241,10 +238,7 @@ def builtin_mode_normalization_rules(
             path_type=PathType.FILE,
             recursive_match=True,
         ),
-        SymbolicMode.parse_filesystem_mode(
-            "a-w",
-            attribute_path['"*.ali"'],
-        ),
+        OctalMode(0o444),
     )
 
     yield (
diff --git a/src/debputy/commands/debputy_cmd/__main__.py b/src/debputy/commands/debputy_cmd/__main__.py
index 27d52ca..3270737 100644
--- a/src/debputy/commands/debputy_cmd/__main__.py
+++ b/src/debputy/commands/debputy_cmd/__main__.py
@@ -660,9 +660,6 @@ def _dh_integration_generate_debs(context: CommandContext) -> None:
     if parsed_args.debug_mode:
         log_level = logging.INFO
     if log_level is not None:
-        _warn(
-            f"LOG LEVEL: {log_level} -- {logging.WARNING} -- {PRINT_COMMAND} -- {logging.INFO}"
-        )
         change_log_level(log_level)
     integration_mode = context.resolve_integration_mode()
     is_dh_rrr_only_mode = integration_mode == INTEGRATION_MODE_DH_DEBPUTY_RRR
diff --git a/src/debputy/commands/debputy_cmd/lint_and_lsp_cmds.py b/src/debputy/commands/debputy_cmd/lint_and_lsp_cmds.py
index 46b536b..eaab750 100644
--- a/src/debputy/commands/debputy_cmd/lint_and_lsp_cmds.py
+++ b/src/debputy/commands/debputy_cmd/lint_and_lsp_cmds.py
@@ -22,21 +22,22 @@ _EDITOR_SNIPPETS = {
         (add-to-list 'auto-mode-alist '("/debian/debputy.manifest\\'" . yaml-mode))
         ;; Inform eglot about the debputy LSP
         (with-eval-after-load 'eglot
-            (add-to-list 'eglot-server-programs
-                    '(debian-control-mode . ("debputy" "lsp" "server" "--ignore-language-ids")))
-            (add-to-list 'eglot-server-programs
-                    '(debian-changelog-mode . ("debputy" "lsp" "server" "--ignore-language-ids")))
-            (add-to-list 'eglot-server-programs
-                    '(debian-copyright-mode . ("debputy" "lsp" "server" "--ignore-language-ids")))
-        ;; Requires elpa-dpkg-dev-el (>= 37.12)
-           (add-to-list 'eglot-server-programs
-                    '(debian-autopkgtest-control-mode . ("debputy" "lsp" "server" "--ignore-language-ids")))
-            ;; The debian/rules file uses the qmake mode.
-            (add-to-list 'eglot-server-programs
-                    '(makefile-gmake-mode . ("debputy" "lsp" "server" "--ignore-language-ids")))
-            (add-to-list 'eglot-server-programs
-                    '(yaml-mode . ("debputy" "lsp" "server" "--ignore-language-ids")))
-        )
+          (add-to-list 'eglot-server-programs
+                       '(
+                         (
+                            ;; Requires elpa-dpkg-dev-el (>= 37.12)
+                            (debian-autopkgtest-control-mode :language-id "debian/tests/control")
+                            ;; Requires elpa-dpkg-dev-el
+                            (debian-control-mode :language-id "debian/control")
+                            (debian-changelog-mode :language-id "debian/changelog")
+                            (debian-copyright-mode :language-id "debian/copyright")
+                            ;; No language id for these atm.
+                            makefile-gmake-mode
+                            ;; Requires elpa-yaml-mode
+                            yaml-mode
+                          )
+                         . ("debputy" "lsp" "server")
+        )))
 
         ;; Auto-start eglot for the relevant modes.
         (add-hook 'debian-control-mode-hook 'eglot-ensure)
@@ -182,7 +183,7 @@ def lsp_server_cmd(context: CommandContext) -> None:
     debputy_language_server.dctrl_parser = context.dctrl_parser
     debputy_language_server.trust_language_ids = parsed_args.trust_language_ids
 
-    debputy_language_server.finish_initialization()
+    debputy_language_server.finish_startup_initialization()
 
     if parsed_args.tcp and parsed_args.ws:
         _error("Sorry, --tcp and --ws are mutually exclusive")
diff --git a/src/debputy/highlevel_manifest_parser.py b/src/debputy/highlevel_manifest_parser.py
index dd97d58..b7a4600 100644
--- a/src/debputy/highlevel_manifest_parser.py
+++ b/src/debputy/highlevel_manifest_parser.py
@@ -214,7 +214,7 @@ class HighLevelManifestParser(ParserContextData):
             if not self.substitution.is_used(var):
                 raise ManifestParseException(
                     f'The variable "{var}" is unused. Either use it or remove it.'
-                    f" The variable was declared at {attribute_path.path}."
+                    f" The variable was declared at {attribute_path.path_key_lc}."
                 )
         if isinstance(self, YAMLManifestParser) and self._mutable_yaml_manifest is None:
             self._mutable_yaml_manifest = MutableYAMLManifest.empty_manifest()
@@ -451,7 +451,7 @@ class YAMLManifestParser(HighLevelManifestParser):
         return v
 
     def from_yaml_dict(self, yaml_data: object) -> "HighLevelManifest":
-        attribute_path = AttributePath.root_path()
+        attribute_path = AttributePath.root_path(yaml_data)
         parser_generator = self._plugin_provided_feature_set.manifest_parser_generator
         dispatchable_object_parsers = parser_generator.dispatchable_object_parsers
         manifest_root_parser = dispatchable_object_parsers[OPARSER_MANIFEST_ROOT]
diff --git a/src/debputy/linting/lint_impl.py b/src/debputy/linting/lint_impl.py
index ddafd4c..ddc7e93 100644
--- a/src/debputy/linting/lint_impl.py
+++ b/src/debputy/linting/lint_impl.py
@@ -6,18 +6,6 @@ import sys
 import textwrap
 from typing import Optional, List, Union, NoReturn, Mapping
 
-from debputy.lsprotocol.types import (
-    CodeAction,
-    Command,
-    CodeActionParams,
-    CodeActionContext,
-    TextDocumentIdentifier,
-    TextEdit,
-    Position,
-    DiagnosticSeverity,
-    Diagnostic,
-)
-
 from debputy.commands.debputy_cmd.context import CommandContext
 from debputy.commands.debputy_cmd.output import _output_styling, OutputStylingBase
 from debputy.filesystem_scan import FSROOverlay
@@ -45,13 +33,13 @@ from debputy.lsp.lsp_debian_tests_control import (
     _lint_debian_tests_control,
     _reformat_debian_tests_control,
 )
-from debputy.lsp.quickfixes import provide_standard_quickfixes_from_diagnostics
-from debputy.lsp.spellchecking import disable_spellchecking
-from debputy.lsp.style_prefs import (
-    StylePreferenceTable,
+from debputy.lsp.maint_prefs import (
+    MaintainerPreferenceTable,
     EffectivePreference,
-    determine_effective_style,
+    determine_effective_preference,
 )
+from debputy.lsp.quickfixes import provide_standard_quickfixes_from_diagnostics
+from debputy.lsp.spellchecking import disable_spellchecking
 from debputy.lsp.text_edit import (
     get_well_formatted_edit,
     merge_sort_text_edits,
@@ -59,6 +47,17 @@ from debputy.lsp.text_edit import (
     OverLappingTextEditException,
 )
 from debputy.lsp.vendoring._deb822_repro import Deb822FileElement
+from debputy.lsprotocol.types import (
+    CodeAction,
+    Command,
+    CodeActionParams,
+    CodeActionContext,
+    TextDocumentIdentifier,
+    TextEdit,
+    Position,
+    DiagnosticSeverity,
+    Diagnostic,
+)
 from debputy.packages import SourcePackage, BinaryPackage
 from debputy.plugin.api import VirtualPath
 from debputy.plugin.api.feature_set import PluginProvidedFeatureSet
@@ -87,20 +86,21 @@ REFORMAT_FORMATS = {
 @dataclasses.dataclass(slots=True)
 class LintContext:
     plugin_feature_set: PluginProvidedFeatureSet
-    style_preference_table: StylePreferenceTable
+    maint_preference_table: MaintainerPreferenceTable
     source_root: Optional[VirtualPath]
     debian_dir: Optional[VirtualPath]
     parsed_deb822_file_content: Optional[Deb822FileElement] = None
     source_package: Optional[SourcePackage] = None
     binary_packages: Optional[Mapping[str, BinaryPackage]] = None
     effective_preference: Optional[EffectivePreference] = None
+    style_tool: Optional[str] = None
     unsupported_preference_reason: Optional[str] = None
     salsa_ci: Optional[CommentedMap] = None
 
     def state_for(self, path: str, content: str, lines: List[str]) -> LintStateImpl:
         return LintStateImpl(
             self.plugin_feature_set,
-            self.style_preference_table,
+            self.maint_preference_table,
             self.source_root,
             self.debian_dir,
             path,
@@ -119,7 +119,7 @@ def gather_lint_info(context: CommandContext) -> LintContext:
         debian_dir = None
     lint_context = LintContext(
         context.load_plugins(),
-        StylePreferenceTable.load_styles(),
+        MaintainerPreferenceTable.load_preferences(),
         source_root,
         debian_dir,
     )
@@ -147,12 +147,13 @@ def gather_lint_info(context: CommandContext) -> LintContext:
         except YAMLError:
             break
     if source_package is not None or salsa_ci_map is not None:
-        pref, pref_reason = determine_effective_style(
-            lint_context.style_preference_table,
+        pref, tool, pref_reason = determine_effective_preference(
+            lint_context.maint_preference_table,
             source_package,
             salsa_ci_map,
         )
         lint_context.effective_preference = pref
+        lint_context.style_tool = tool
         lint_context.unsupported_preference_reason = pref_reason
 
     return lint_context
@@ -237,9 +238,9 @@ def perform_reformat(
     fo = _output_styling(context.parsed_args, sys.stdout)
     lint_context = gather_lint_info(context)
     if named_style is not None:
-        style = lint_context.style_preference_table.named_styles.get(named_style)
+        style = lint_context.maint_preference_table.named_styles.get(named_style)
         if style is None:
-            styles = ", ".join(lint_context.style_preference_table.named_styles)
+            styles = ", ".join(lint_context.maint_preference_table.named_styles)
             _error(f'There is no style named "{style}". Options include: {styles}')
         if (
             lint_context.effective_preference is not None
@@ -257,10 +258,15 @@ def perform_reformat(
                 "While `debputy` could identify a formatting for this package, it does not support it."
             )
             _warn(f"{lint_context.unsupported_preference_reason}")
+            if lint_context.style_tool is not None:
+                _info(
+                    f"The following tool might be able to apply the style: {lint_context.style_tool}"
+                )
             if parsed_args.supported_style_required:
                 _error(
                     "Sorry; `debputy` does not support the style. Use --unknown-or-unsupported-style-is-ok to make"
-                    " this a non-error."
+                    " this a non-error (note that `debputy` will not reformat the packaging in this case; just not"
+                    " exit with an error code)."
                 )
         else:
             print(
@@ -293,6 +299,11 @@ def perform_reformat(
                 )
             )
             if parsed_args.supported_style_required:
+                if lint_context.style_tool is not None:
+                    _error(
+                        "Sorry, `debputy reformat` does not support the packaging style. However, the"
+                        f" formatting is supposedly handled by: {lint_context.style_tool}"
+                    )
                 _error(
                     "Sorry; `debputy` does not know which style to use for this package. Please either set a"
                     "style or use --unknown-or-unsupported-style-is-ok to make this a non-error"
diff --git a/src/debputy/linting/lint_util.py b/src/debputy/linting/lint_util.py
index 1ed881c..6346508 100644
--- a/src/debputy/linting/lint_util.py
+++ b/src/debputy/linting/lint_util.py
@@ -41,8 +41,8 @@ from debputy.util import _warn
 
 if TYPE_CHECKING:
     from debputy.lsp.text_util import LintCapablePositionCodec
-    from debputy.lsp.style_prefs import (
-        StylePreferenceTable,
+    from debputy.lsp.maint_prefs import (
+        MaintainerPreferenceTable,
         EffectivePreference,
     )
 
@@ -110,7 +110,7 @@ class LintState:
         raise NotImplementedError
 
     @property
-    def style_preference_table(self) -> "StylePreferenceTable":
+    def maint_preference_table(self) -> "MaintainerPreferenceTable":
         raise NotImplementedError
 
     @property
@@ -129,7 +129,7 @@ class LintState:
 @dataclasses.dataclass(slots=True)
 class LintStateImpl(LintState):
     plugin_feature_set: PluginProvidedFeatureSet = dataclasses.field(repr=False)
-    style_preference_table: "StylePreferenceTable" = dataclasses.field(repr=False)
+    maint_preference_table: "MaintainerPreferenceTable" = dataclasses.field(repr=False)
     source_root: Optional[VirtualPathBase]
     debian_dir: Optional[VirtualPathBase]
     path: str
diff --git a/src/debputy/lsp/apt_cache.py b/src/debputy/lsp/apt_cache.py
new file mode 100644
index 0000000..45988a7
--- /dev/null
+++ b/src/debputy/lsp/apt_cache.py
@@ -0,0 +1,167 @@
+import asyncio
+import dataclasses
+import subprocess
+import sys
+from collections import defaultdict
+from typing import Literal, Optional, Sequence, Iterable, Mapping
+
+from debian.deb822 import Deb822
+from debian.debian_support import Version
+
+AptCacheState = Literal[
+    "not-loaded",
+    "loading",
+    "loaded",
+    "failed",
+    "tooling-not-available",
+    "empty-cache",
+]
+
+
+@dataclasses.dataclass(slots=True)
+class PackageInformation:
+    name: str
+    architecture: str
+    version: Version
+    multi_arch: str
+    # suites: Sequence[Tuple[str, ...]]
+    synopsis: str
+    section: str
+    provides: Optional[str]
+    upstream_homepage: Optional[str]
+
+
+@dataclasses.dataclass(slots=True, frozen=True)
+class PackageLookup:
+    name: str
+    package: Optional[PackageInformation]
+    provided_by: Sequence[PackageInformation]
+
+
+class AptCache:
+
+    def __init__(self) -> None:
+        self._state: AptCacheState = "not-loaded"
+        self._load_error: Optional[str] = None
+        self._lookups: Mapping[str, PackageLookup] = {}
+
+    @property
+    def state(self) -> AptCacheState:
+        return self._state
+
+    @property
+    def load_error(self) -> Optional[str]:
+        return self._load_error
+
+    def lookup(self, name: str) -> Optional[PackageLookup]:
+        return self._lookups.get(name)
+
+    async def load(self) -> None:
+        if self._state in ("loading", "loaded"):
+            raise RuntimeError(f"Already {self._state}")
+        self._load_error = None
+        self._state = "loading"
+        try:
+            files_raw = subprocess.check_output(
+                [
+                    "apt-get",
+                    "indextargets",
+                    "--format",
+                    "$(IDENTIFIER)\x1f$(FILENAME)",
+                ]
+            ).decode("utf-8")
+        except FileNotFoundError:
+            self._state = "tooling-not-available"
+            self._load_error = "apt-get not available in PATH"
+            return
+        except subprocess.CalledProcessError as e:
+            self._state = "failed"
+            self._load_error = f"apt-get exited with {e.returncode}"
+            return
+        packages = {}
+        for raw_file_line in files_raw.split("\n"):
+            if not raw_file_line or raw_file_line.isspace():
+                continue
+            identifier, filename = raw_file_line.split("\x1f")
+            if identifier not in ("Packages",):
+                continue
+            try:
+                for package_info in parse_apt_file(filename):
+                    # Let other computations happen if needed.
+                    await asyncio.sleep(0)
+                    existing = packages.get(package_info.name)
+                    if existing and package_info.version < existing.version:
+                        continue
+                    packages[package_info.name] = package_info
+            except FileNotFoundError:
+                self._state = "tooling-not-available"
+                self._load_error = "/usr/lib/apt/apt-helper not available"
+                return
+            except (AttributeError, RuntimeError, IndexError) as e:
+                self._state = "failed"
+                self._load_error = str(e)
+                return
+        provides = defaultdict(list)
+        for package_info in packages.values():
+            if not package_info.provides:
+                continue
+            # Some packages (`debhelper`) provides the same package multiple times (`debhelper-compat`).
+            # Normalize that into one.
+            deps = {
+                clause.split("(")[0].strip()
+                for clause in package_info.provides.split(",")
+            }
+            for dep in sorted(deps):
+                provides[dep].append(package_info)
+
+        self._lookups = {
+            name: PackageLookup(
+                name,
+                packages.get(name),
+                tuple(provides.get(name, [])),
+            )
+            for name in packages.keys() | provides.keys()
+        }
+        self._state = "loaded"
+
+
+def parse_apt_file(filename: str) -> Iterable[PackageInformation]:
+    proc = subprocess.Popen(
+        ["/usr/lib/apt/apt-helper", "cat-file", filename],
+        stdin=subprocess.DEVNULL,
+        stdout=subprocess.PIPE,
+    )
+    with proc:
+        for stanza in Deb822.iter_paragraphs(proc.stdout):
+            pkg_info = stanza_to_package_info(stanza)
+            if pkg_info is not None:
+                yield pkg_info
+
+
+def stanza_to_package_info(stanza: Deb822) -> Optional[PackageInformation]:
+    try:
+        name = stanza["Package"]
+        architecture = sys.intern(stanza["Architecture"])
+        version = Version(stanza["Version"])
+        multi_arch = sys.intern(stanza.get("Multi-Arch", "no"))
+        synopsis = stanza["Description"]
+        section = sys.intern(stanza["Section"])
+        provides = stanza.get("Provides")
+        homepage = stanza.get("Homepage")
+    except KeyError:
+        return None
+    if "\n" in synopsis:
+        # "Modern" Packages files do not have the full description. But in case we see a (very old one)
+        # have consistent behavior with the modern ones.
+        synopsis = synopsis.split("\n")[0]
+
+    return PackageInformation(
+        name,
+        architecture,
+        version,
+        multi_arch,
+        synopsis,
+        section,
+        provides,
+        homepage,
+    )
diff --git a/src/debputy/lsp/debputy_ls.py b/src/debputy/lsp/debputy_ls.py
index eb4162f..a1475b2 100644
--- a/src/debputy/lsp/debputy_ls.py
+++ b/src/debputy/lsp/debputy_ls.py
@@ -1,5 +1,6 @@
 import dataclasses
 import os
+import time
 from typing import (
     Optional,
     List,
@@ -17,19 +18,19 @@ from debputy.dh.dh_assistant import (
     DhSequencerData,
     extract_dh_addons_from_control,
 )
-from debputy.lsprotocol.types import MarkupKind
-
 from debputy.filesystem_scan import FSROOverlay, VirtualPathBase
 from debputy.linting.lint_util import (
     LintState,
 )
-from debputy.lsp.style_prefs import (
-    StylePreferenceTable,
+from debputy.lsp.apt_cache import AptCache
+from debputy.lsp.maint_prefs import (
+    MaintainerPreferenceTable,
     MaintainerPreference,
-    determine_effective_style,
+    determine_effective_preference,
 )
 from debputy.lsp.text_util import LintCapablePositionCodec
 from debputy.lsp.vendoring._deb822_repro import Deb822FileElement, parse_deb822_file
+from debputy.lsprotocol.types import MarkupKind
 from debputy.packages import (
     SourcePackage,
     BinaryPackage,
@@ -301,16 +302,16 @@ class LSProvidedLintState(LintState):
         salsa_ci = self._resolve_salsa_ci()
         if source_package is None and salsa_ci is None:
             return None
-        style, _ = determine_effective_style(
-            self.style_preference_table,
+        style, _, _ = determine_effective_preference(
+            self.maint_preference_table,
             source_package,
             salsa_ci,
         )
         return style
 
     @property
-    def style_preference_table(self) -> StylePreferenceTable:
-        return self._ls.style_preferences
+    def maint_preference_table(self) -> MaintainerPreferenceTable:
+        return self._ls.maint_preferences
 
     @property
     def salsa_ci(self) -> Optional[CommentedMap]:
@@ -360,20 +361,42 @@ class DebputyLanguageServer(LanguageServer):
         self._plugin_feature_set: Optional[PluginProvidedFeatureSet] = None
         self._trust_language_ids: Optional[bool] = None
         self._finished_initialization = False
-        self.style_preferences = StylePreferenceTable({}, {})
+        self.maint_preferences = MaintainerPreferenceTable({}, {})
+        self.apt_cache = AptCache()
+        self.background_tasks = set()
 
-    def finish_initialization(self) -> None:
+    def finish_startup_initialization(self) -> None:
         if self._finished_initialization:
             return
         assert self._dctrl_parser is not None
         assert self._plugin_feature_set is not None
         assert self._trust_language_ids is not None
-        self.style_preferences = self.style_preferences.load_styles()
+        self.maint_preferences = self.maint_preferences.load_preferences()
         _info(
-            f"Loaded style preferences: {len(self.style_preferences.maintainer_preferences)} unique maintainer preferences recorded"
+            f"Loaded style preferences: {len(self.maint_preferences.maintainer_preferences)} unique maintainer preferences recorded"
         )
         self._finished_initialization = True
 
+    async def on_initialize(self) -> None:
+        task = self.loop.create_task(self._load_apt_cache(), name="Index apt cache")
+        self.background_tasks.add(task)
+        task.add_done_callback(self.background_tasks.discard)
+
+    def shutdown(self) -> None:
+        for task in self.background_tasks:
+            _info(f"Cancelling task: {task.get_name()}")
+            self.loop.call_soon_threadsafe(task.cancel)
+        return super().shutdown()
+
+    async def _load_apt_cache(self) -> None:
+        _info("Starting load of apt cache data")
+        start = time.time()
+        await self.apt_cache.load()
+        end = time.time()
+        _info(
+            f"Loading apt cache finished after {end-start} seconds and is now in state {self.apt_cache.state}"
+        )
+
     @property
     def plugin_feature_set(self) -> PluginProvidedFeatureSet:
         res = self._plugin_feature_set
diff --git a/src/debputy/lsp/lsp_debian_control.py b/src/debputy/lsp/lsp_debian_control.py
index 5a72222..2b8f9b0 100644
--- a/src/debputy/lsp/lsp_debian_control.py
+++ b/src/debputy/lsp/lsp_debian_control.py
@@ -2,6 +2,7 @@ import dataclasses
 import os.path
 import re
 import textwrap
+from itertools import chain
 from typing import (
     Union,
     Sequence,
@@ -17,6 +18,7 @@ from debputy.analysis.analysis_util import flatten_ppfs
 from debputy.analysis.debian_dir import resolve_debhelper_config_files
 from debputy.dh.dh_assistant import extract_dh_compat_level
 from debputy.linting.lint_util import LintState
+from debputy.lsp.apt_cache import PackageLookup
 from debputy.lsp.debputy_ls import DebputyLanguageServer
 from debputy.lsp.diagnostics import DiagnosticData
 from debputy.lsp.lsp_debian_control_reference_data import (
@@ -27,6 +29,7 @@ from debputy.lsp.lsp_debian_control_reference_data import (
     package_name_to_section,
     all_package_relationship_fields,
     extract_first_value_and_position,
+    all_source_relationship_fields,
 )
 from debputy.lsp.lsp_features import (
     lint_diagnostics,
@@ -99,7 +102,7 @@ from debputy.packager_provided_files import (
     detect_all_packager_provided_files,
 )
 from debputy.plugin.api.impl import plugin_metadata_for_debputys_own_plugin
-from debputy.util import detect_possible_typo
+from debputy.util import detect_possible_typo, PKGNAME_REGEX, _info
 
 try:
     from debputy.lsp.vendoring._deb822_repro.locatable import (
@@ -311,58 +314,12 @@ def _debian_control_hover(
     return deb822_hover(ls, params, _DCTRL_FILE_METADATA, custom_handler=_custom_hover)
 
 
-def _custom_hover(
-    server_position: Position,
-    _current_field: Optional[str],
+def _custom_hover_description(
+    _ls: "DebputyLanguageServer",
+    _known_field: DctrlKnownField,
+    line: str,
     _word_at_position: str,
-    known_field: Optional[DctrlKnownField],
-    in_value: bool,
-    _doc: "TextDocument",
-    lines: List[str],
 ) -> Optional[Union[Hover, str]]:
-    if not in_value:
-        return None
-
-    line_no = server_position.line
-    line = lines[line_no]
-    substvar_search_ref = server_position.character
-    substvar = ""
-    try:
-        if line and line[substvar_search_ref] in ("$", "{"):
-            substvar_search_ref += 2
-        substvar_start = line.rindex("${", 0, substvar_search_ref)
-        substvar_end = line.index("}", substvar_start)
-        if server_position.character <= substvar_end:
-            substvar = line[substvar_start : substvar_end + 1]
-    except (ValueError, IndexError):
-        pass
-
-    if substvar == "${}" or _SUBSTVAR_RE.fullmatch(substvar):
-        substvar_md = _SUBSTVARS_DOC.get(substvar)
-
-        computed_doc = ""
-        for_field = relationship_substvar_for_field(substvar)
-        if for_field:
-            # Leading empty line is intentional!
-            computed_doc = textwrap.dedent(
-                f"""
-                This substvar is a relationship substvar for the field {for_field}.
-                Relationship substvars are automatically added in the field they
-                are named after in `debhelper-compat (= 14)` or later, or with
-                `debputy` (any integration mode after 0.1.21).
-            """
-            )
-
-        if substvar_md is None:
-            doc = f"No documentation for {substvar}.\n"
-            md_fields = ""
-        else:
-            doc = substvar_md.description
-            md_fields = "\n" + substvar_md.render_metadata_fields()
-        return f"# Substvar `{substvar}`\n\n{doc}{computed_doc}{md_fields}"
-
-    if known_field is None or known_field.name != "Description":
-        return None
     if line[0].isspace():
         return None
     try:
@@ -405,7 +362,7 @@ def _custom_hover(
            package name already and it generally does not help the user
            understand what they are looking at.
          * In many situations, the user will only see the package name
-           and its synopsis. The synopsis must standalone.
+           and its synopsis. The synopsis must be able to stand alone.
 
         **Example renderings in various terminal UIs**:
         ```
@@ -450,6 +407,240 @@ def _custom_hover(
     )
 
 
+def _render_package_lookup(
+    package_lookup: PackageLookup,
+    known_field: DctrlKnownField,
+) -> str:
+    name = package_lookup.name
+    provider = package_lookup.package
+    if package_lookup.package is None and len(package_lookup.provided_by) == 1:
+        provider = package_lookup.provided_by[0]
+
+    if provider:
+        segments = [
+            f"# {name} ({provider.version}, {provider.architecture}) ",
+            "",
+        ]
+
+        if (
+            _is_bd_field(known_field)
+            and name.startswith("dh-sequence-")
+            and len(name) > 12
+        ):
+            sequence = name[12:]
+            segments.append(
+                f"This build-dependency will activate the `dh` sequence called `{sequence}`."
+            )
+            segments.append("")
+        segments.extend(
+            [
+                f"Synopsis: {provider.synopsis}",
+                f"Multi-Arch: {provider.multi_arch}",
+                f"Section: {provider.section}",
+            ]
+        )
+        if provider.upstream_homepage is not None:
+            segments.append(f"Upstream homepage: {provider.upstream_homepage}")
+        segments.append("")
+        segments.append(
+            "Data is from the system's APT cache, which may not match the target distribution."
+        )
+        return "\n".join(segments)
+
+    segments = [
+        f"# {name} [virtual]",
+        "",
+        "The package {name} is a virtual package provided by one of:",
+    ]
+    segments.extend(f" * {p.name}" for p in package_lookup.provided_by)
+    segments.append("")
+    segments.append(
+        "Data is from the system's APT cache, which may not match the target distribution."
+    )
+    return "\n".join(segments)
+
+
+def _disclaimer(is_empty: bool) -> str:
+    if is_empty:
+        return textwrap.dedent(
+            """\
+        The system's APT cache is empty, so it was not possible to verify that the
+        package exist.
+"""
+        )
+    return textwrap.dedent(
+        """\
+        The package is not known by the APT cache on this system, so there may be typo
+        or the package may not be available in the version of your distribution.
+"""
+    )
+
+
+def _render_package_by_name(
+    name: str, known_field: DctrlKnownField, is_empty: bool
+) -> Optional[str]:
+    if _is_bd_field(known_field) and name.startswith("dh-sequence-") and len(name) > 12:
+        sequence = name[12:]
+        return (
+            textwrap.dedent(
+                f"""\
+        # {name}
+
+        This build-dependency will activate the `dh` sequence called `{sequence}`.
+
+        """
+            )
+            + _disclaimer(is_empty)
+        )
+    return (
+        textwrap.dedent(
+            f"""\
+        # {name}
+
+    """
+        )
+        + _disclaimer(is_empty)
+    )
+
+
+def _is_bd_field(known_field: DctrlKnownField) -> bool:
+    return known_field.name in (
+        "Build-Depends",
+        "Build-Depends-Arch",
+        "Build-Depends-Indep",
+    )
+
+
+def _custom_hover_relationship_field(
+    ls: "DebputyLanguageServer",
+    known_field: DctrlKnownField,
+    _line: str,
+    word_at_position: str,
+) -> Optional[Union[Hover, str]]:
+    apt_cache = ls.apt_cache
+    state = apt_cache.state
+    is_empty = False
+    _info(f"Rel field: {known_field.name} - {word_at_position} - {state}")
+    if "|" in word_at_position:
+        return textwrap.dedent(
+            f"""\
+            Sorry, no hover docs for OR relations at the moment.
+
+            The relation being matched: `{word_at_position}`
+
+            The code is missing logic to determine which side of the OR the lookup is happening.
+        """
+        )
+    match = next(iter(PKGNAME_REGEX.finditer(word_at_position)), None)
+    if match is None:
+        return
+    package = match.group()
+    if state == "empty-cache":
+        state = "loaded"
+        is_empty = True
+    if state == "loaded":
+        result = apt_cache.lookup(package)
+        if result is None:
+            return _render_package_by_name(
+                package,
+                known_field,
+                is_empty=is_empty,
+            )
+        return _render_package_lookup(result, known_field)
+
+    if state in (
+        "not-loaded",
+        "failed",
+        "tooling-not-available",
+    ):
+        details = apt_cache.load_error if apt_cache.load_error else "N/A"
+        return textwrap.dedent(
+            f"""\
+        Sorry, the APT cache data is not available due to an error or missing tool.
+
+        Details: {details}
+        """
+        )
+
+    if state == "empty-cache":
+        return f"Cannot lookup {package}: APT cache data was empty"
+
+    if state == "loading":
+        return f"Cannot lookup {package}: APT cache data is still being indexed. Please try again in a moment."
+    return None
+
+
+_CUSTOM_FIELD_HOVER = {
+    field: _custom_hover_relationship_field
+    for field in chain(
+        all_package_relationship_fields().values(),
+        all_source_relationship_fields().values(),
+    )
+    if field != "Provides"
+}
+
+_CUSTOM_FIELD_HOVER["Description"] = _custom_hover_description
+
+
+def _custom_hover(
+    ls: "DebputyLanguageServer",
+    server_position: Position,
+    _current_field: Optional[str],
+    word_at_position: str,
+    known_field: Optional[DctrlKnownField],
+    in_value: bool,
+    _doc: "TextDocument",
+    lines: List[str],
+) -> Optional[Union[Hover, str]]:
+    if not in_value:
+        return None
+
+    line_no = server_position.line
+    line = lines[line_no]
+    substvar_search_ref = server_position.character
+    substvar = ""
+    try:
+        if line and line[substvar_search_ref] in ("$", "{"):
+            substvar_search_ref += 2
+        substvar_start = line.rindex("${", 0, substvar_search_ref)
+        substvar_end = line.index("}", substvar_start)
+        if server_position.character <= substvar_end:
+            substvar = line[substvar_start : substvar_end + 1]
+    except (ValueError, IndexError):
+        pass
+
+    if substvar == "${}" or _SUBSTVAR_RE.fullmatch(substvar):
+        substvar_md = _SUBSTVARS_DOC.get(substvar)
+
+        computed_doc = ""
+        for_field = relationship_substvar_for_field(substvar)
+        if for_field:
+            # Leading empty line is intentional!
+            computed_doc = textwrap.dedent(
+                f"""
+                This substvar is a relationship substvar for the field {for_field}.
+                Relationship substvars are automatically added in the field they
+                are named after in `debhelper-compat (= 14)` or later, or with
+                `debputy` (any integration mode after 0.1.21).
+            """
+            )
+
+        if substvar_md is None:
+            doc = f"No documentation for {substvar}.\n"
+            md_fields = ""
+        else:
+            doc = substvar_md.description
+            md_fields = "\n" + substvar_md.render_metadata_fields()
+        return f"# Substvar `{substvar}`\n\n{doc}{computed_doc}{md_fields}"
+
+    if known_field is None:
+        return None
+    dispatch = _CUSTOM_FIELD_HOVER.get(known_field.name)
+    if dispatch is None:
+        return None
+    return dispatch(ls, known_field, line, word_at_position)
+
+
 @lsp_completer(_LANGUAGE_IDS)
 def _debian_control_completions(
     ls: "DebputyLanguageServer",
diff --git a/src/debputy/lsp/lsp_debian_control_reference_data.py b/src/debputy/lsp/lsp_debian_control_reference_data.py
index 007c0dd..2ec885b 100644
--- a/src/debputy/lsp/lsp_debian_control_reference_data.py
+++ b/src/debputy/lsp/lsp_debian_control_reference_data.py
@@ -104,7 +104,7 @@ except ImportError:
 
 
 if TYPE_CHECKING:
-    from debputy.lsp.style_prefs import EffectivePreference
+    from debputy.lsp.maint_prefs import EffectivePreference
 
 
 F = TypeVar("F", bound="Deb822KnownField")
diff --git a/src/debputy/lsp/lsp_debian_debputy_manifest.py b/src/debputy/lsp/lsp_debian_debputy_manifest.py
index 15e9aa6..a8a2fdf 100644
--- a/src/debputy/lsp/lsp_debian_debputy_manifest.py
+++ b/src/debputy/lsp/lsp_debian_debputy_manifest.py
@@ -752,7 +752,6 @@ def debputy_manifest_completer(
     server_position = doc.position_codec.position_from_client_units(
         lines, params.position
     )
-    attribute_root_path = AttributePath.root_path()
     orig_line = lines[server_position.line].rstrip()
     has_colon = ":" in orig_line
     added_key = _insert_snippet(lines, server_position)
@@ -791,6 +790,7 @@ def debputy_manifest_completer(
         context = lines[server_position.line].replace("\n", "\\n")
         _info(f"Completion failed: parse error: Line in question: {context}")
         return None
+    attribute_root_path = AttributePath.root_path(content)
     m = _trace_cursor(content, attribute_root_path, server_position)
 
     if m is None:
@@ -925,13 +925,13 @@ def debputy_manifest_hover(
     doc = ls.workspace.get_text_document(params.text_document.uri)
     lines = doc.lines
     position_codec = doc.position_codec
-    attribute_root_path = AttributePath.root_path()
     server_position = position_codec.position_from_client_units(lines, params.position)
 
     try:
         content = MANIFEST_YAML.load("".join(lines))
     except YAMLError:
         return None
+    attribute_root_path = AttributePath.root_path(content)
     m = _trace_cursor(content, attribute_root_path, server_position)
     if m is None:
         _info("No match")
diff --git a/src/debputy/lsp/lsp_dispatch.py b/src/debputy/lsp/lsp_dispatch.py
index 27170d0..b5e61dc 100644
--- a/src/debputy/lsp/lsp_dispatch.py
+++ b/src/debputy/lsp/lsp_dispatch.py
@@ -54,6 +54,8 @@ from debputy.lsprotocol.types import (
     TEXT_DOCUMENT_WILL_SAVE_WAIT_UNTIL,
     WillSaveTextDocumentParams,
     TEXT_DOCUMENT_FORMATTING,
+    INITIALIZE,
+    InitializeParams,
 )
 
 _DOCUMENT_VERSION_TABLE: Dict[str, int] = {}
@@ -94,6 +96,14 @@ def is_doc_at_version(uri: str, version: int) -> bool:
     return dv == version
 
 
+@DEBPUTY_LANGUAGE_SERVER.feature(INITIALIZE)
+async def _on_initialize(
+    ls: "DebputyLanguageServer",
+    _: InitializeParams,
+) -> None:
+    await ls.on_initialize()
+
+
 @DEBPUTY_LANGUAGE_SERVER.feature(TEXT_DOCUMENT_DID_OPEN)
 async def _open_document(
     ls: "DebputyLanguageServer",
diff --git a/src/debputy/lsp/lsp_generic_deb822.py b/src/debputy/lsp/lsp_generic_deb822.py
index 895a3e0..4340abc 100644
--- a/src/debputy/lsp/lsp_generic_deb822.py
+++ b/src/debputy/lsp/lsp_generic_deb822.py
@@ -311,6 +311,7 @@ def deb822_hover(
     custom_handler: Optional[
         Callable[
             [
+                "DebputyLanguageServer",
                 Position,
                 Optional[str],
                 str,
@@ -351,6 +352,7 @@ def deb822_hover(
     hover_text = None
     if custom_handler is not None:
         res = custom_handler(
+            ls,
             server_pos,
             current_field,
             word_at_position,
diff --git a/src/debputy/lsp/lsp_self_check.py b/src/debputy/lsp/lsp_self_check.py
index aa28a56..ec0c7e7 100644
--- a/src/debputy/lsp/lsp_self_check.py
+++ b/src/debputy/lsp/lsp_self_check.py
@@ -110,7 +110,7 @@ def spell_checking() -> bool:
 
 
 @lsp_generic_check(
-    feature_name="Extra dh support",
+    feature_name="extra dh support",
     problem="Missing dependencies",
     how_to_fix="Run `apt satisfy debhelper (>= 13.16~)` to enable this feature",
 )
@@ -135,6 +135,30 @@ def check_dh_version() -> bool:
         return Version(parts[0]) >= Version("13.16~")
 
 
+@lsp_generic_check(
+    feature_name="apt cache packages",
+    problem="Missing apt or empty apt cache",
+    how_to_fix="",
+)
+def check_apt_cache() -> bool:
+    try:
+        output = subprocess.check_output(
+            [
+                "apt-get",
+                "indextargets",
+                "--format",
+                "$(IDENTIFIER)",
+            ]
+        ).decode("utf-8")
+    except (FileNotFoundError, subprocess.CalledProcessError):
+        return False
+    for line in output.splitlines():
+        if line.strip() == "Packages":
+            return True
+
+    return False
+
+
 def assert_can_start_lsp() -> None:
     for self_check in LSP_CHECKS:
         if self_check.is_mandatory and not self_check.test():
diff --git a/src/debputy/lsp/style-preferences.yaml b/src/debputy/lsp/maint-preferences.yaml
index 982f242..982f242 100644
--- a/src/debputy/lsp/style-preferences.yaml
+++ b/src/debputy/lsp/maint-preferences.yaml
diff --git a/src/debputy/lsp/style_prefs.py b/src/debputy/lsp/maint_prefs.py
index 1bcd800..fa6315b 100644
--- a/src/debputy/lsp/style_prefs.py
+++ b/src/debputy/lsp/maint_prefs.py
@@ -23,14 +23,14 @@ from debputy.lsp.lsp_reference_keyword import ALL_PUBLIC_NAMED_STYLES
 from debputy.lsp.vendoring._deb822_repro.types import FormatterCallback
 from debputy.lsp.vendoring.wrap_and_sort import wrap_and_sort_formatter
 from debputy.packages import SourcePackage
-from debputy.util import _error, _info
+from debputy.util import _error
 from debputy.yaml import MANIFEST_YAML
 from debputy.yaml.compat import CommentedMap
 
 PT = TypeVar("PT", bool, str, int)
 
 
-BUILTIN_STYLES = os.path.join(os.path.dirname(__file__), "style-preferences.yaml")
+BUILTIN_STYLES = os.path.join(os.path.dirname(__file__), "maint-preferences.yaml")
 
 _NORMALISE_FIELD_CONTENT_KEY = ["formatting", "deb822", "normalize-field-content"]
 _UPLOADER_SPLIT_RE = re.compile(r"(?<=>)\s*,")
@@ -458,7 +458,7 @@ class MaintainerPreference(EffectivePreference):
         return EffectivePreference(**fields)
 
 
-class StylePreferenceTable:
+class MaintainerPreferenceTable:
 
     def __init__(
         self,
@@ -469,7 +469,7 @@ class StylePreferenceTable:
         self._maintainer_preferences = maintainer_preferences
 
     @classmethod
-    def load_styles(cls) -> Self:
+    def load_preferences(cls) -> Self:
         named_styles: Dict[str, EffectivePreference] = {}
         maintainer_preferences: Dict[str, MaintainerPreference] = {}
         with open(BUILTIN_STYLES) as fd:
@@ -565,16 +565,16 @@ def extract_maint_email(maint: str) -> str:
     return maint[idx + 1 : -1]
 
 
-def determine_effective_style(
-    style_preference_table: StylePreferenceTable,
+def determine_effective_preference(
+    maint_preference_table: MaintainerPreferenceTable,
     source_package: Optional[SourcePackage],
     salsa_ci: Optional[CommentedMap],
-) -> Tuple[Optional[EffectivePreference], Optional[str]]:
+) -> Tuple[Optional[EffectivePreference], Optional[str], Optional[str]]:
     style = source_package.fields.get("X-Style") if source_package is not None else None
     if style is not None:
         if style not in ALL_PUBLIC_NAMED_STYLES:
-            return None, "X-Style contained an unknown/unsupported style"
-        return style_preference_table.named_styles.get(style), None
+            return None, None, "X-Style contained an unknown/unsupported style"
+        return maint_preference_table.named_styles.get(style), "debputy reformat", None
 
     if salsa_ci:
         disable_wrap_and_sort = salsa_ci.mlget(
@@ -600,53 +600,73 @@ def determine_effective_style(
             if wrap_and_sort_options is None:
                 wrap_and_sort_options = ""
             elif not isinstance(wrap_and_sort_options, str):
-                return None, "The salsa-ci had a non-string option for wrap-and-sort"
+                return (
+                    None,
+                    None,
+                    "The salsa-ci had a non-string option for wrap-and-sort",
+                )
             detected_style = parse_salsa_ci_wrap_and_sort_args(wrap_and_sort_options)
+            tool_w_args = f"wrap-and-sort {wrap_and_sort_options}".strip()
             if detected_style is None:
                 msg = "One or more of the wrap-and-sort options in the salsa-ci file was not supported"
             else:
                 msg = None
-            return detected_style, msg
+            return detected_style, tool_w_args, msg
 
     if source_package is None:
-        return None, None
+        return None, None, None
 
     maint = source_package.fields.get("Maintainer")
     if maint is None:
-        return None, None
+        return None, None, None
     maint_email = extract_maint_email(maint)
-    maint_style = style_preference_table.maintainer_preferences.get(maint_email)
+    maint_style = maint_preference_table.maintainer_preferences.get(maint_email)
     # Special-case "@packages.debian.org" when missing, since they are likely to be "ad-hoc"
     # teams that will not be registered. In that case, we fall back to looking at the uploader
     # preferences as-if the maintainer had not been listed at all.
     if maint_style is None and not maint_email.endswith("@packages.debian.org"):
-        return None, None
+        return None, None, None
     if maint_style is not None and maint_style.is_packaging_team:
         # When the maintainer is registered as a packaging team, then we assume the packaging
         # team's style applies unconditionally.
-        return maint_style.as_effective_pref(), None
+        effective = maint_style.as_effective_pref()
+        tool_w_args = _guess_tool_from_style(maint_preference_table, effective)
+        return effective, tool_w_args, None
     uploaders = source_package.fields.get("Uploaders")
     if uploaders is None:
         detected_style = (
             maint_style.as_effective_pref() if maint_style is not None else None
         )
-        return detected_style, None
+        tool_w_args = _guess_tool_from_style(maint_preference_table, detected_style)
+        return detected_style, tool_w_args, None
     all_styles: List[Optional[EffectivePreference]] = []
     if maint_style is not None:
         all_styles.append(maint_style)
     for uploader in _UPLOADER_SPLIT_RE.split(uploaders):
         uploader_email = extract_maint_email(uploader)
-        uploader_style = style_preference_table.maintainer_preferences.get(
+        uploader_style = maint_preference_table.maintainer_preferences.get(
             uploader_email
         )
         all_styles.append(uploader_style)
 
     if not all_styles:
-        return None, None
+        return None, None, None
     r = functools.reduce(EffectivePreference.aligned_preference, all_styles)
     if isinstance(r, MaintainerPreference):
-        return r.as_effective_pref(), None
-    return r, None
+        r = r.as_effective_pref()
+    tool_w_args = _guess_tool_from_style(maint_preference_table, r)
+    return r, tool_w_args, None
+
+
+def _guess_tool_from_style(
+    maint_preference_table: MaintainerPreferenceTable,
+    pref: Optional[EffectivePreference],
+) -> Optional[str]:
+    if pref is None:
+        return None
+    if maint_preference_table.named_styles["black"] == pref:
+        return "debputy reformat"
+    return None
 
 
 def _split_options(args: Iterable[str]) -> Iterable[str]:
diff --git a/src/debputy/manifest_parser/declarative_parser.py b/src/debputy/manifest_parser/declarative_parser.py
index 4a32368..6cbbce3 100644
--- a/src/debputy/manifest_parser/declarative_parser.py
+++ b/src/debputy/manifest_parser/declarative_parser.py
@@ -349,16 +349,16 @@ class DeclarativeMappingInputParser(DeclarativeInputParser[TD], Generic[TD, SF])
             if unused_keys:
                 k = ", ".join(unused_keys)
                 raise ManifestParseException(
-                    f'Unknown keys "{unknown_keys}" at {path.path}".  Keys that could be used here are: {k}.{doc_ref}'
+                    f'Unknown keys "{unknown_keys}" at {path.path_container_lc}".  Keys that could be used here are: {k}.{doc_ref}'
                 )
             raise ManifestParseException(
-                f'Unknown keys "{unknown_keys}" at {path.path}".  Please remove them.{doc_ref}'
+                f'Unknown keys "{unknown_keys}" at {path.path_container_lc}".  Please remove them.{doc_ref}'
             )
         missing_keys = self.input_time_required_parameters - value.keys()
         if missing_keys:
             required = ", ".join(repr(k) for k in sorted(missing_keys))
             raise ManifestParseException(
-                f"The following keys were required but not present at {path.path}: {required}{doc_ref}"
+                f"The following keys were required but not present at {path.path_container_lc}: {required}{doc_ref}"
             )
         for maybe_required in self.all_parameters - value.keys():
             attr = self.manifest_attributes[maybe_required]
@@ -371,14 +371,14 @@ class DeclarativeMappingInputParser(DeclarativeInputParser[TD], Generic[TD, SF])
             ):
                 reason = attr.conditional_required.reason
                 raise ManifestParseException(
-                    f'Missing the *conditionally* required attribute "{maybe_required}" at {path.path}. {reason}{doc_ref}'
+                    f'Missing the *conditionally* required attribute "{maybe_required}" at {path.path_container_lc}. {reason}{doc_ref}'
                 )
         for keyset in self.at_least_one_of:
             matched_keys = value.keys() & keyset
             if not matched_keys:
                 conditionally_required = ", ".join(repr(k) for k in sorted(keyset))
                 raise ManifestParseException(
-                    f"At least one of the following keys must be present at {path.path}:"
+                    f"At least one of the following keys must be present at {path.path_container_lc}:"
                     f" {conditionally_required}{doc_ref}"
                 )
         for group in self.mutually_exclusive_attributes:
@@ -386,7 +386,7 @@ class DeclarativeMappingInputParser(DeclarativeInputParser[TD], Generic[TD, SF])
             if len(matched) > 1:
                 ck = ", ".join(repr(k) for k in sorted(matched))
                 raise ManifestParseException(
-                    f"Could not parse {path.path}: The following attributes are"
+                    f"Could not parse {path.path_container_lc}: The following attributes are"
                     f" mutually exclusive: {ck}{doc_ref}"
                 )
 
diff --git a/src/debputy/manifest_parser/util.py b/src/debputy/manifest_parser/util.py
index a9cbbe8..bcaa617 100644
--- a/src/debputy/manifest_parser/util.py
+++ b/src/debputy/manifest_parser/util.py
@@ -14,8 +14,11 @@ from typing import (
     TYPE_CHECKING,
     Iterable,
     Container,
+    Literal,
 )
 
+from debputy.yaml.compat import CommentedBase
+
 from debputy.manifest_parser.exceptions import ManifestParseException
 
 if TYPE_CHECKING:
@@ -28,26 +31,29 @@ StrOrInt = Union[str, int]
 AttributePathAliasMapping = Mapping[
     StrOrInt, Tuple[StrOrInt, Optional["AttributePathAliasMapping"]]
 ]
+LineReportKind = Literal["key", "value", "container"]
 
 
-class AttributePath(object):
-    __slots__ = ("parent", "name", "alias_mapping", "path_hint")
+class AttributePath:
+    __slots__ = ("parent", "container", "name", "alias_mapping", "path_hint")
 
     def __init__(
         self,
         parent: Optional["AttributePath"],
         key: Optional[Union[str, int]],
         *,
+        container: Optional[Any] = None,
         alias_mapping: Optional[AttributePathAliasMapping] = None,
     ) -> None:
         self.parent = parent
+        self.container = container
         self.name = key
         self.path_hint: Optional[str] = None
         self.alias_mapping = alias_mapping
 
     @classmethod
-    def root_path(cls) -> "AttributePath":
-        return AttributePath(None, None)
+    def root_path(cls, container: Optional[Any]) -> "AttributePath":
+        return AttributePath(None, None, container=container)
 
     @classmethod
     def builtin_path(cls) -> "AttributePath":
@@ -70,8 +76,29 @@ class AttributePath(object):
         segments.reverse()
         yield from (s.name for s in segments)
 
-    @property
-    def path(self) -> str:
+    def _resolve_path(self, report_kind: LineReportKind) -> str:
+        parent = self.parent
+        key = self.name
+        if report_kind == "container":
+            key = parent.name if parent else None
+            parent = parent.parent if parent else None
+        container = parent.container if parent is not None else None
+
+        if isinstance(container, CommentedBase):
+            lc = container.lc
+            try:
+                if isinstance(key, str):
+                    if report_kind == "key":
+                        lc_data = lc.key(key)
+                    else:
+                        lc_data = lc.value(key)
+                else:
+                    lc_data = lc.item(key)
+            except (AttributeError, RuntimeError, LookupError):
+                lc_data = None
+        else:
+            lc_data = None
+
         segments = list(self._iter_path())
         segments.reverse()
         parts: List[str] = []
@@ -88,12 +115,31 @@ class AttributePath(object):
                 if parts:
                     parts.append(".")
                 parts.append(k)
-        if path_hint:
+
+        if lc_data is not None:
+            line_pos, col = lc_data
+            # Translate 0-based (index) to 1-based (line number)
+            line_pos += 1
+            parts.append(f" [Line {line_pos} column {col}]")
+
+        elif path_hint:
             parts.append(f" <Search for: {path_hint}>")
         if not parts:
             return "document root"
         return "".join(parts)
 
+    @property
+    def path_container_lc(self) -> str:
+        return self._resolve_path("container")
+
+    @property
+    def path_key_lc(self) -> str:
+        return self._resolve_path("key")
+
+    @property
+    def path(self) -> str:
+        return self._resolve_path("value")
+
     def __str__(self) -> str:
         return self.path
 
@@ -106,9 +152,25 @@ class AttributePath(object):
                 if item == "":
                     # Support `sources[0]` mapping to `source` by `sources -> source` and `0 -> ""`.
                     return AttributePath(
-                        self.parent, self.name, alias_mapping=alias_mapping
+                        self.parent,
+                        self.name,
+                        alias_mapping=alias_mapping,
+                        container=self.container,
                     )
-        return AttributePath(self, item, alias_mapping=alias_mapping)
+        container = self.container
+        if container is not None:
+            try:
+                child_container = self.container[item]
+            except (AttributeError, RuntimeError, LookupError):
+                child_container = None
+        else:
+            child_container = None
+        return AttributePath(
+            self,
+            item,
+            alias_mapping=alias_mapping,
+            container=child_container,
+        )
 
     def _iter_path(self) -> Iterator["AttributePath"]:
         current = self
diff --git a/src/debputy/plugin/api/impl.py b/src/debputy/plugin/api/impl.py
index 6369663..b0674fb 100644
--- a/src/debputy/plugin/api/impl.py
+++ b/src/debputy/plugin/api/impl.py
@@ -1867,7 +1867,7 @@ def parse_json_plugin_desc(
             f" clash with the bundled plugin of same name."
         )
 
-    attribute_path = AttributePath.root_path()
+    attribute_path = AttributePath.root_path(raw)
 
     try:
         plugin_json_metadata = PLUGIN_METADATA_PARSER.parse_input(
diff --git a/src/debputy/plugin/api/impl_types.py b/src/debputy/plugin/api/impl_types.py
index 77e96ea..1a9bfdf 100644
--- a/src/debputy/plugin/api/impl_types.py
+++ b/src/debputy/plugin/api/impl_types.py
@@ -587,11 +587,11 @@ class DispatchingObjectParser(
             )
         if not isinstance(orig_value, dict):
             raise ManifestParseException(
-                f"The attribute {attribute_path.path} must be a non-empty mapping.{doc_ref}"
+                f"The attribute {attribute_path.path_container_lc} must be a non-empty mapping.{doc_ref}"
             )
         if not orig_value:
             raise ManifestParseException(
-                f"The attribute {attribute_path.path} must be a non-empty mapping.{doc_ref}"
+                f"The attribute {attribute_path.path_container_lc} must be a non-empty mapping.{doc_ref}"
             )
         result = {}
         unknown_keys = orig_value.keys() - self._parsers.keys()
@@ -675,7 +675,7 @@ class InPackageContextParser(
             )
         if not isinstance(orig_value, dict) or not orig_value:
             raise ManifestParseException(
-                f"The attribute {attribute_path.path} must be a non-empty mapping.{doc_ref}"
+                f"The attribute {attribute_path.path_container_lc} must be a non-empty mapping.{doc_ref}"
             )
         delegate = self.delegate
         result = {}
diff --git a/src/debputy/plugin/debputy/manifest_root_rules.py b/src/debputy/plugin/debputy/manifest_root_rules.py
index 80a4799..1d3b096 100644
--- a/src/debputy/plugin/debputy/manifest_root_rules.py
+++ b/src/debputy/plugin/debputy/manifest_root_rules.py
@@ -212,13 +212,13 @@ def _handle_manifest_variables(
         key_path = variables_path[key]
         if not SUBST_VAR_RE.match("{{" + key + "}}"):
             raise ManifestParseException(
-                f"The variable at {key_path.path} has an invalid name and therefore cannot"
+                f"The variable at {key_path.path_key_lc} has an invalid name and therefore cannot"
                 " be used."
             )
         if substitution.variable_state(key) != VariableNameState.UNDEFINED:
             raise ManifestParseException(
                 f'The variable "{key}" is already reserved/defined. Error triggered by'
-                f" {key_path.path}."
+                f" {key_path.path_key_lc}."
             )
         try:
             value = substitution.substitute(value_raw, key_path.path)
diff --git a/tests/lint_tests/lint_tutil.py b/tests/lint_tests/lint_tutil.py
index 74e08db..c32ad3c 100644
--- a/tests/lint_tests/lint_tutil.py
+++ b/tests/lint_tests/lint_tutil.py
@@ -9,7 +9,7 @@ from debputy.linting.lint_util import (
     LintStateImpl,
     LintState,
 )
-from debputy.lsp.style_prefs import StylePreferenceTable, EffectivePreference
+from debputy.lsp.maint_prefs import MaintainerPreferenceTable, EffectivePreference
 from debputy.packages import DctrlParser
 from debputy.plugin.api.feature_set import PluginProvidedFeatureSet
 
@@ -42,7 +42,7 @@ class LintWrapper:
         self.path = path
         self._dctrl_parser = dctrl_parser
         self.source_root: Optional[VirtualPathBase] = None
-        self.lint_style_preference_table = StylePreferenceTable({}, {})
+        self.lint_maint_preference_table = MaintainerPreferenceTable({}, {})
         self.effective_preference: Optional[EffectivePreference] = None
 
     def __call__(self, lines: List[str]) -> Optional[List["Diagnostic"]]:
@@ -59,7 +59,7 @@ class LintWrapper:
         debian_dir = source_root.get("debian") if source_root is not None else None
         state = LintStateImpl(
             self._debputy_plugin_feature_set,
-            self.lint_style_preference_table,
+            self.lint_maint_preference_table,
             source_root,
             debian_dir,
             self.path,
diff --git a/tests/test_fs_metadata.py b/tests/test_fs_metadata.py
index 7dd3d55..3cbbb03 100644
--- a/tests/test_fs_metadata.py
+++ b/tests/test_fs_metadata.py
@@ -132,7 +132,9 @@ def test_mtime_clamp_and_builtin_dir_mode(
     verify_paths(intermediate_manifest, path_defs)
 
 
-def test_transformations_create_symlink(manifest_parser_pkg_foo):
+def test_transformations_create_symlink(
+    manifest_parser_pkg_foo: YAMLManifestParser,
+) -> None:
     content = textwrap.dedent(
         """\
     manifest-version: '0.1'
@@ -178,7 +180,9 @@ def test_transformations_create_symlink(manifest_parser_pkg_foo):
     verify_paths(intermediate_manifest, expected_results)
 
 
-def test_transformations_create_symlink_replace_success(manifest_parser_pkg_foo):
+def test_transformations_create_symlink_replace_success(
+    manifest_parser_pkg_foo: YAMLManifestParser,
+) -> None:
     content = textwrap.dedent(
         """\
     manifest-version: '0.1'
@@ -230,8 +234,10 @@ def test_transformations_create_symlink_replace_success(manifest_parser_pkg_foo)
     ],
 )
 def test_transformations_create_symlink_replace_failure(
-    manifest_parser_pkg_foo, replacement_rule, reason
-):
+    manifest_parser_pkg_foo: YAMLManifestParser,
+    replacement_rule: str,
+    reason: str,
+) -> None:
     content = textwrap.dedent(
         f"""\
     manifest-version: '0.1'
@@ -257,14 +263,15 @@ def test_transformations_create_symlink_replace_failure(
         f"Refusing to replace ./usr/share/foo with a symlink; {reason} and the active"
         f" replacement-rule was {replacement_rule}.  You can set the replacement-rule to"
         ' "discard-existing", if you are not interested in the contents of ./usr/share/foo. This error'
-        " was triggered by packages.foo.transformations[0].create-symlink <Search for: usr/share/foo>."
+        # Ideally, this would be reported for line 5.
+        " was triggered by packages.foo.transformations[0].create-symlink [Line 6 column 18]."
     )
     assert e_info.value.args[0] == msg
 
 
 def test_transformations_create_symlink_replace_with_explicit_remove(
-    manifest_parser_pkg_foo,
-):
+    manifest_parser_pkg_foo: YAMLManifestParser,
+) -> None:
     content = textwrap.dedent(
         """\
     manifest-version: '0.1'
@@ -299,8 +306,8 @@ def test_transformations_create_symlink_replace_with_explicit_remove(
 
 
 def test_transformations_create_symlink_replace_with_replacement_rule(
-    manifest_parser_pkg_foo,
-):
+    manifest_parser_pkg_foo: YAMLManifestParser,
+) -> None:
     content = textwrap.dedent(
         """\
     manifest-version: '0.1'
@@ -335,7 +342,9 @@ def test_transformations_create_symlink_replace_with_replacement_rule(
     verify_paths(intermediate_manifest, expected_results)
 
 
-def test_transformations_path_metadata(manifest_parser_pkg_foo):
+def test_transformations_path_metadata(
+    manifest_parser_pkg_foo: YAMLManifestParser,
+) -> None:
     content = textwrap.dedent(
         """\
     manifest-version: '0.1'
@@ -382,7 +391,9 @@ def test_transformations_path_metadata(manifest_parser_pkg_foo):
     verify_paths(intermediate_manifest, expected_results)
 
 
-def test_transformations_directories(manifest_parser_pkg_foo):
+def test_transformations_directories(
+    manifest_parser_pkg_foo: YAMLManifestParser,
+) -> None:
     content = textwrap.dedent(
         """\
     manifest-version: '0.1'
@@ -453,7 +464,9 @@ def test_transformations_directories(manifest_parser_pkg_foo):
     verify_paths(intermediate_manifest, expected_results)
 
 
-def test_transformation_remove(manifest_parser_pkg_foo):
+def test_transformation_remove(
+    manifest_parser_pkg_foo: YAMLManifestParser,
+) -> None:
     content = textwrap.dedent(
         """\
     manifest-version: '0.1'
@@ -489,7 +502,9 @@ def test_transformation_remove(manifest_parser_pkg_foo):
     verify_paths(intermediate_manifest, expected_results)
 
 
-def test_transformation_remove_keep_empty(manifest_parser_pkg_foo):
+def test_transformation_remove_keep_empty(
+    manifest_parser_pkg_foo: YAMLManifestParser,
+) -> None:
     content = textwrap.dedent(
         """\
     manifest-version: '0.1'
@@ -529,7 +544,9 @@ def test_transformation_remove_keep_empty(manifest_parser_pkg_foo):
     verify_paths(intermediate_manifest, expected_results)
 
 
-def test_transformation_remove_glob(manifest_parser_pkg_foo):
+def test_transformation_remove_glob(
+    manifest_parser_pkg_foo: YAMLManifestParser,
+) -> None:
     content = textwrap.dedent(
         """\
     manifest-version: '0.1'
@@ -581,7 +598,9 @@ def test_transformation_remove_glob(manifest_parser_pkg_foo):
     verify_paths(intermediate_manifest, expected_results)
 
 
-def test_transformation_remove_no_match(manifest_parser_pkg_foo):
+def test_transformation_remove_no_match(
+    manifest_parser_pkg_foo: YAMLManifestParser,
+) -> None:
     content = textwrap.dedent(
         """\
     manifest-version: '0.1'
@@ -612,13 +631,15 @@ def test_transformation_remove_no_match(manifest_parser_pkg_foo):
         manifest.apply_to_binary_staging_directory("foo", fs_root, claim_mtime_to)
     expected = (
         'The match rule "./some/non-existing-path" in transformation'
-        ' "packages.foo.transformations[0].remove <Search for: some/non-existing-path>" did not match any paths. Either'
+        ' "packages.foo.transformations[0].remove [Line 5 column 18]" did not match any paths. Either'
         " the definition is redundant (and can be omitted) or the match rule is incorrect."
     )
     assert expected == e_info.value.args[0]
 
 
-def test_transformation_move_basic(manifest_parser_pkg_foo):
+def test_transformation_move_basic(
+    manifest_parser_pkg_foo: YAMLManifestParser,
+) -> None:
     content = textwrap.dedent(
         """\
     manifest-version: '0.1'
@@ -682,7 +703,9 @@ def test_transformation_move_basic(manifest_parser_pkg_foo):
     verify_paths(intermediate_manifest, expected_results)
 
 
-def test_transformation_move_no_match(manifest_parser_pkg_foo):
+def test_transformation_move_no_match(
+    manifest_parser_pkg_foo: YAMLManifestParser,
+) -> None:
     content = textwrap.dedent(
         """\
     manifest-version: '0.1'
@@ -715,13 +738,15 @@ def test_transformation_move_no_match(manifest_parser_pkg_foo):
         manifest.apply_to_binary_staging_directory("foo", fs_root, claim_mtime_to)
     expected = (
         'The match rule "./some/non-existing-path" in transformation'
-        ' "packages.foo.transformations[0].move <Search for: some/non-existing-path>" did not match any paths. Either'
+        ' "packages.foo.transformations[0].move [Line 6 column 12]" did not match any paths. Either'
         " the definition is redundant (and can be omitted) or the match rule is incorrect."
     )
     assert expected == e_info.value.args[0]
 
 
-def test_builtin_mode_normalization(manifest_parser_pkg_foo):
+def test_builtin_mode_normalization_shell_scripts(
+    manifest_parser_pkg_foo: YAMLManifestParser,
+) -> None:
     manifest = manifest_parser_pkg_foo.build_manifest()
     claim_mtime_to = 255
     sh_script_content = "#!/bin/sh"
@@ -773,3 +798,53 @@ def test_builtin_mode_normalization(manifest_parser_pkg_foo):
     print(intermediate_manifest)
 
     verify_paths(intermediate_manifest, expected_results)
+
+
+def test_builtin_mode_normalization(
+    manifest_parser_pkg_foo: YAMLManifestParser,
+) -> None:
+    manifest = manifest_parser_pkg_foo.build_manifest()
+    claim_mtime_to = 255
+
+    paths = [
+        virtual_path_def("usr/", mode=0o755, mtime=10, fs_path="/nowhere/usr"),
+        virtual_path_def(
+            "usr/share/", mode=0o755, mtime=10, fs_path="/nowhere/usr/share"
+        ),
+        virtual_path_def(
+            "usr/share/perl5/", mode=0o755, mtime=10, fs_path="/nowhere/usr/share/perl5"
+        ),
+        virtual_path_def(
+            "usr/share/perl5/Foo.pm",
+            # #1076346
+            mode=0o444,
+            mtime=10,
+            fs_path="/nowhere/Foo.pm",
+        ),
+        virtual_path_def(
+            "usr/share/perl5/Bar.pm",
+            mode=0o755,
+            mtime=10,
+            fs_path="/nowhere/Bar.pm",
+        ),
+    ]
+
+    fs_root = build_virtual_fs(paths, read_write_fs=True)
+    assert [p.name for p in manifest.all_packages] == ["foo"]
+
+    expected_results = [
+        ("usr/", Expected(mode=0o755, mtime=10)),
+        ("usr/share/", Expected(mode=0o755, mtime=10)),
+        ("usr/share/perl5/", Expected(mode=0o755, mtime=10)),
+        ("usr/share/perl5/Bar.pm", Expected(mode=0o644, mtime=10)),
+        ("usr/share/perl5/Foo.pm", Expected(mode=0o644, mtime=10)),
+    ]
+    assert [p.name for p in manifest.all_packages] == ["foo"]
+
+    intermediate_manifest = manifest.apply_to_binary_staging_directory(
+        "foo", fs_root, claim_mtime_to
+    )
+
+    print(intermediate_manifest)
+
+    verify_paths(intermediate_manifest, expected_results)
diff --git a/tests/test_install_rules.py b/tests/test_install_rules.py
index a361864..e94e8bc 100644
--- a/tests/test_install_rules.py
+++ b/tests/test_install_rules.py
@@ -620,7 +620,7 @@ def test_install_rules_no_matches(manifest_parser_pkg_foo) -> None:
         )
     expected_msg = (
         "There were no matches for build/private-arch-tool in /nowhere/debian/tmp, /nowhere"
-        " (definition: installations[0].install <Search for: build/private-arch-tool>)."
+        " (definition: installations[0].install [Line 5 column 6])."
         " Match rule: ./build/private-arch-tool (the exact path / no globbing)"
     )
     assert e_info.value.message == expected_msg
diff --git a/tests/test_parser.py b/tests/test_parser.py
index 4aee024..1c84445 100644
--- a/tests/test_parser.py
+++ b/tests/test_parser.py
@@ -124,7 +124,10 @@ def test_parsing_variables_reserved(manifest_parser_pkg_foo, varname):
     with pytest.raises(ManifestParseException) as e_info:
         manifest_parser_pkg_foo.parse_manifest(fd=content)
 
-    msg = f'The variable "{varname}" is already reserved/defined. Error triggered by definitions.variables.{varname}.'
+    msg = (
+        f'The variable "{varname}" is already reserved/defined.'
+        f" Error triggered by definitions.variables.{varname} [Line 4 column 4]."
+    )
     assert normalize_doc_link(e_info.value.args[0]) == msg
 
 
@@ -163,7 +166,7 @@ def test_parsing_variables_unused(manifest_parser_pkg_foo):
 
     msg = (
         'The variable "UNUSED" is unused. Either use it or remove it.'
-        " The variable was declared at definitions.variables.UNUSED."
+        " The variable was declared at definitions.variables.UNUSED [Line 4 column 4]."
     )
     assert normalize_doc_link(e_info.value.args[0]) == msg
 
@@ -181,7 +184,7 @@ def test_parsing_package_foo_empty(manifest_parser_pkg_foo):
         manifest_parser_pkg_foo.parse_manifest(fd=content)
 
     msg = (
-        "The attribute packages.foo must be a non-empty mapping. Please see"
+        "The attribute packages.foo [Line 3 column 4] must be a non-empty mapping. Please see"
         " {{DEBPUTY_DOC_ROOT_DIR}}/MANIFEST-FORMAT.md#binary-package-rules for the documentation."
     )
     assert normalize_doc_link(e_info.value.args[0]) == msg
@@ -238,8 +241,8 @@ def test_create_symlinks_missing_path(manifest_parser_pkg_foo):
         manifest_parser_pkg_foo.parse_manifest(fd=content)
 
     msg = (
-        "The following keys were required but not present at packages.foo.transformations[0].create-symlink: 'path'"
-        " (Documentation: "
+        "The following keys were required but not present at packages.foo.transformations[0].create-symlink"
+        " [Line 5 column 12]: 'path' (Documentation: "
         "{{DEBPUTY_DOC_ROOT_DIR}}/MANIFEST-FORMAT.md#create-symlinks-transformation-rule-create-symlink)"
     )
     assert normalize_doc_link(e_info.value.args[0]) == msg
@@ -263,7 +266,7 @@ def test_create_symlinks_unknown_replacement_rule(manifest_parser_pkg_foo):
         manifest_parser_pkg_foo.parse_manifest(fd=content)
 
     msg = (
-        'The attribute "packages.foo.transformations[0].create-symlink.replacement-rule <Search for: usr/share/foo>"'
+        'The attribute "packages.foo.transformations[0].create-symlink.replacement-rule [Line 8 column 32]"'
         " did not have a valid structure/type: Value (golf) must be one of the following literal values:"
         ' "error-if-exists", "error-if-directory", "abort-on-non-empty-directory", "discard-existing"'
     )
@@ -286,8 +289,8 @@ def test_create_symlinks_missing_target(manifest_parser_pkg_foo):
         manifest_parser_pkg_foo.parse_manifest(fd=content)
 
     msg = (
-        "The following keys were required but not present at packages.foo.transformations[0].create-symlink: 'target'"
-        " (Documentation: "
+        "The following keys were required but not present at packages.foo.transformations[0].create-symlink"
+        " [Line 5 column 12]: 'target' (Documentation: "
         "{{DEBPUTY_DOC_ROOT_DIR}}/MANIFEST-FORMAT.md#create-symlinks-transformation-rule-create-symlink)"
     )
     assert normalize_doc_link(e_info.value.args[0]) == msg
@@ -310,7 +313,7 @@ def test_create_symlinks_not_normalized_path(manifest_parser_pkg_foo):
         manifest_parser_pkg_foo.parse_manifest(fd=content)
 
     expected = (
-        'The path "../bar" provided in packages.foo.transformations[0].create-symlink.path <Search for: ../bar>'
+        'The path "../bar" provided in packages.foo.transformations[0].create-symlink.path [Line 6 column 20]'
         ' should be relative to the root of the package and not use any ".." or "." segments.'
     )
     assert e_info.value.args[0] == expected
@@ -332,7 +335,7 @@ def test_unresolvable_subst_in_source_context(manifest_parser_pkg_foo):
 
     expected = (
         "The variable {{PACKAGE}} is not available while processing installations[0].install.as"
-        " <Search for: foo.sh>."
+        " [Line 5 column 7]."
     )
 
     assert e_info.value.args[0] == expected
@@ -397,7 +400,7 @@ def test_yaml_octal_mode_int(manifest_parser_pkg_foo):
         manifest_parser_pkg_foo.parse_manifest(fd=content)
 
     msg = (
-        'The attribute "packages.foo.transformations[0].path-metadata.mode <Search for: usr/share/bar>" did not'
+        'The attribute "packages.foo.transformations[0].path-metadata.mode [Line 7 column 20]" did not'
         " have a valid structure/type: The attribute must be a FileSystemMode (string)"
     )
 
diff --git a/tests/test_style.py b/tests/test_style.py
index ef6ddc4..d3cfb14 100644
--- a/tests/test_style.py
+++ b/tests/test_style.py
@@ -4,9 +4,9 @@ import pytest
 from debian.deb822 import Deb822
 from debputy.yaml.compat import CommentedMap
 
-from debputy.lsp.style_prefs import (
-    StylePreferenceTable,
-    determine_effective_style,
+from debputy.lsp.maint_prefs import (
+    MaintainerPreferenceTable,
+    determine_effective_preference,
     EffectivePreference,
     _WAS_DEFAULTS,
 )
@@ -14,7 +14,7 @@ from debputy.packages import SourcePackage
 
 
 def test_load_styles() -> None:
-    styles = StylePreferenceTable.load_styles()
+    styles = MaintainerPreferenceTable.load_preferences()
     assert "niels@thykier.net" in styles.maintainer_preferences
     nt_style = styles.maintainer_preferences["niels@thykier.net"]
     # Note this is data dependent; if it fails because the style changes, update the test
@@ -32,7 +32,7 @@ def test_load_styles() -> None:
 
 
 def test_load_named_styles() -> None:
-    styles = StylePreferenceTable.load_styles()
+    styles = MaintainerPreferenceTable.load_preferences()
     assert "black" in styles.named_styles
     black_style = styles.named_styles["black"]
     # Note this is data dependent; if it fails because the style changes, update the test
@@ -48,7 +48,7 @@ def test_load_named_styles() -> None:
 
 
 def test_compat_styles() -> None:
-    styles = StylePreferenceTable.load_styles()
+    styles = MaintainerPreferenceTable.load_preferences()
 
     # Data dependent; if it breaks, provide a stubbed style preference table
     assert "niels@thykier.net" in styles.maintainer_preferences
@@ -71,30 +71,33 @@ def test_compat_styles() -> None:
     )
     src = SourcePackage(fields)
 
-    effective_style, _ = determine_effective_style(styles, src, None)
+    effective_style, tool, _ = determine_effective_preference(styles, src, None)
     assert effective_style == nt_pref
+    assert tool == "debputy reformat"
 
     fields["Uploaders"] = (
         "Niels Thykier <niels@thykier.net>, Chris Hofstaedtler <zeha@debian.org>"
     )
     src = SourcePackage(fields)
 
-    effective_style, _ = determine_effective_style(styles, src, None)
+    effective_style, tool, _ = determine_effective_preference(styles, src, None)
     assert effective_style == nt_pref
     assert effective_style == zeha_pref
+    assert tool == "debputy reformat"
 
     fields["Uploaders"] = (
         "Niels Thykier <niels@thykier.net>, Chris Hofstaedtler <zeha@debian.org>, Random Developer <random@example.org>"
     )
     src = SourcePackage(fields)
 
-    effective_style, _ = determine_effective_style(styles, src, None)
+    effective_style, tool, _ = determine_effective_preference(styles, src, None)
     assert effective_style is None
+    assert tool is None
 
 
 @pytest.mark.xfail
 def test_compat_styles_team_maint() -> None:
-    styles = StylePreferenceTable.load_styles()
+    styles = MaintainerPreferenceTable.load_preferences()
     fields = Deb822(
         {
             "Package": "foo",
@@ -108,12 +111,13 @@ def test_compat_styles_team_maint() -> None:
     assert "random@example.org" not in styles.maintainer_preferences
     team_style = styles.maintainer_preferences["team@lists.debian.org"]
     assert team_style.is_packaging_team
-    effective_style, _ = determine_effective_style(styles, src, None)
+    effective_style, tool, _ = determine_effective_preference(styles, src, None)
     assert effective_style == team_style.as_effective_pref()
+    assert tool is None
 
 
 def test_x_style() -> None:
-    styles = StylePreferenceTable.load_styles()
+    styles = MaintainerPreferenceTable.load_preferences()
     fields = Deb822(
         {
             "Package": "foo",
@@ -125,12 +129,13 @@ def test_x_style() -> None:
     assert "random@example.org" not in styles.maintainer_preferences
     assert "black" in styles.named_styles
     black_style = styles.named_styles["black"]
-    effective_style, _ = determine_effective_style(styles, src, None)
+    effective_style, tool, _ = determine_effective_preference(styles, src, None)
     assert effective_style == black_style
+    assert tool == "debputy reformat"
 
 
 def test_was_from_salsa_ci_style() -> None:
-    styles = StylePreferenceTable.load_styles()
+    styles = MaintainerPreferenceTable.load_preferences()
     fields = Deb822(
         {
             "Package": "foo",
@@ -139,20 +144,23 @@ def test_was_from_salsa_ci_style() -> None:
     )
     src = SourcePackage(fields)
     assert "random@example.org" not in styles.maintainer_preferences
-    effective_style, _ = determine_effective_style(styles, src, None)
+    effective_style, tool, _ = determine_effective_preference(styles, src, None)
     assert effective_style is None
+    assert tool is None
     salsa_ci = CommentedMap(
         {"variables": CommentedMap({"SALSA_CI_DISABLE_WRAP_AND_SORT": "yes"})}
     )
-    effective_style, _ = determine_effective_style(styles, src, salsa_ci)
+    effective_style, tool, _ = determine_effective_preference(styles, src, salsa_ci)
     assert effective_style is None
+    assert tool is None
 
     salsa_ci = CommentedMap(
         {"variables": CommentedMap({"SALSA_CI_DISABLE_WRAP_AND_SORT": "no"})}
     )
-    effective_style, _ = determine_effective_style(styles, src, salsa_ci)
+    effective_style, tool, _ = determine_effective_preference(styles, src, salsa_ci)
     was_style = EffectivePreference(**_WAS_DEFAULTS)
     assert effective_style == was_style
+    assert tool == "wrap-and-sort"
 
 
 @pytest.mark.parametrize(
@@ -197,9 +205,10 @@ def test_was_from_salsa_ci_style() -> None:
     ],
 )
 def test_was_from_salsa_ci_style_args(
-    was_args: str, style_delta: Optional[Mapping[str, Any]]
+    was_args: str,
+    style_delta: Optional[Mapping[str, Any]],
 ) -> None:
-    styles = StylePreferenceTable.load_styles()
+    styles = MaintainerPreferenceTable.load_preferences()
     fields = Deb822(
         {
             "Package": "foo",
@@ -218,12 +227,14 @@ def test_was_from_salsa_ci_style_args(
             )
         }
     )
-    effective_style, _ = determine_effective_style(styles, src, salsa_ci)
+    effective_style, tool, _ = determine_effective_preference(styles, src, salsa_ci)
     if style_delta is None:
         assert effective_style is None
+        assert tool is None
     else:
         was_style = EffectivePreference(**_WAS_DEFAULTS).replace(
             **style_delta,
         )
 
         assert effective_style == was_style
+        assert tool == f"wrap-and-sort {was_args}".strip()