diff --git a/build/mach_initialize.py b/build/mach_initialize.py
index d22bdd356955..e28068800966 100644
--- a/build/mach_initialize.py
+++ b/build/mach_initialize.py
@@ -119,7 +119,7 @@ def _maybe_activate_mozillabuild_environment():
             os.environ["PATH"] += f"{os.pathsep}{new_path}"
 
 
-def initialize(topsrcdir, args=()):
+def initialize(topsrcdir):
     # This directory was deleted in bug 1666345, but there may be some ignored
     # files here. We can safely just delete it for the user so they don't have
     # to clean the repo themselves.
@@ -139,7 +139,7 @@ def initialize(topsrcdir, args=()):
         )
     ]
 
-    from mach.util import get_state_dir, get_virtualenv_base_dir, setenv
+    from mach.util import get_state_dir, setenv
 
     state_dir = _create_state_dir()
 
@@ -155,269 +155,216 @@ def initialize(topsrcdir, args=()):
 
     # Centralized registry of available mach commands
     MACH_COMMANDS = {
-        "addtest": MachCommandReference("testing/mach_commands.py"),
-        "addwidget": MachCommandReference("toolkit/content/widgets/mach_commands.py"),
-        "android": MachCommandReference("mobile/android/mach_commands.py"),
-        "android-emulator": MachCommandReference("mobile/android/mach_commands.py"),
-        "artifact": MachCommandReference(
-            "python/mozbuild/mozbuild/artifact_commands.py", "build"
-        ),
-        "awsy-test": MachCommandReference("testing/awsy/mach_commands.py"),
-        "bootstrap": MachCommandReference(
-            "python/mozboot/mozboot/mach_commands.py", "build"
-        ),
-        "browsertime": MachCommandReference("tools/browsertime/mach_commands.py"),
-        "build": MachCommandReference(
-            "python/mozbuild/mozbuild/build_commands.py",
-            "build",
-        ),
-        "build-backend": MachCommandReference(
-            "python/mozbuild/mozbuild/build_commands.py",
-            "build",
-        ),
-        "buildsymbols": MachCommandReference(
-            "python/mozbuild/mozbuild/mach_commands.py"
-        ),
-        "busted": MachCommandReference("tools/mach_commands.py"),
-        "cargo": MachCommandReference("python/mozbuild/mozbuild/mach_commands.py"),
-        "clang-format": MachCommandReference(
-            "python/mozbuild/mozbuild/code_analysis/mach_commands.py"
-        ),
-        "clang-tidy": MachCommandReference(
-            "python/mozbuild/mozbuild/code_analysis/mach_commands.py"
-        ),
-        "clobber": MachCommandReference("python/mozbuild/mozbuild/mach_commands.py"),
-        "compare-locales": MachCommandReference(
-            "tools/compare-locales/mach_commands.py"
-        ),
-        "compileflags": MachCommandReference(
-            "python/mozbuild/mozbuild/compilation/codecomplete.py"
-        ),
-        "configure": MachCommandReference("python/mozbuild/mozbuild/build_commands.py"),
-        "cppunittest": MachCommandReference("testing/mach_commands.py"),
-        "cramtest": MachCommandReference("testing/mach_commands.py"),
-        "crashtest": MachCommandReference("layout/tools/reftest/mach_commands.py"),
-        "data-review": MachCommandReference(
-            "toolkit/components/glean/build_scripts/mach_commands.py"
-        ),
+        "valgrind-test": MachCommandReference("build/valgrind/mach_commands.py"),
         "devtools-css-db": MachCommandReference(
             "devtools/shared/css/generated/mach_commands.py"
         ),
-        "doc": MachCommandReference("tools/moztreedocs/mach_commands.py", "docs"),
-        "doctor": MachCommandReference("python/mozbuild/mozbuild/mach_commands.py"),
-        "environment": MachCommandReference(
-            "python/mozbuild/mozbuild/mach_commands.py"
-        ),
-        "eslint": MachCommandReference("tools/lint/mach_commands.py"),
-        "esmify": MachCommandReference("tools/esmify/mach_commands.py"),
-        "fetch-condprofile": MachCommandReference(
-            "testing/condprofile/mach_commands.py"
-        ),
-        "file-info": MachCommandReference(
-            "python/mozbuild/mozbuild/frontend/mach_commands.py"
-        ),
-        "firefox-ui-functional": MachCommandReference(
-            "testing/firefox-ui/mach_commands.py"
-        ),
-        "fluent-migration-test": MachCommandReference("testing/mach_commands.py"),
-        "format": MachCommandReference("tools/lint/mach_commands.py"),
-        "geckodriver": MachCommandReference("testing/geckodriver/mach_commands.py"),
-        "geckoview-junit": MachCommandReference("testing/mochitest/mach_commands.py"),
-        "generate-test-certs": MachCommandReference(
-            "security/manager/tools/mach_commands.py"
-        ),
-        "gradle": MachCommandReference("mobile/android/mach_commands.py"),
-        "gradle-install": MachCommandReference("mobile/android/mach_commands.py"),
-        "gtest": MachCommandReference("python/mozbuild/mozbuild/mach_commands.py"),
+        "webidl-example": MachCommandReference("dom/bindings/mach_commands.py"),
+        "webidl-parser-test": MachCommandReference("dom/bindings/mach_commands.py"),
         "hazards": MachCommandReference(
             "js/src/devtools/rootAnalysis/mach_commands.py"
         ),
-        "ide": MachCommandReference(
-            "python/mozbuild/mozbuild/backend/mach_commands.py", "build"
-        ),
-        "import-pr": MachCommandReference("tools/vcs/mach_commands.py"),
-        "install": MachCommandReference("python/mozbuild/mozbuild/mach_commands.py"),
-        "install-moz-phab": MachCommandReference("tools/phabricator/mach_commands.py"),
-        "jit-test": MachCommandReference("testing/mach_commands.py"),
-        "jsapi-tests": MachCommandReference("testing/mach_commands.py"),
-        "jsshell-bench": MachCommandReference("testing/mach_commands.py"),
+        "reftest": MachCommandReference("layout/tools/reftest/mach_commands.py"),
         "jstestbrowser": MachCommandReference("layout/tools/reftest/mach_commands.py"),
-        "jstests": MachCommandReference("testing/mach_commands.py"),
-        "l10n-cross-channel": MachCommandReference(
-            "tools/compare-locales/mach_commands.py"
-        ),
-        "lint": MachCommandReference("tools/lint/mach_commands.py", "lint"),
-        "logspam": MachCommandReference("tools/mach_commands.py"),
+        "crashtest": MachCommandReference("layout/tools/reftest/mach_commands.py"),
+        "android": MachCommandReference("mobile/android/mach_commands.py"),
+        "gradle": MachCommandReference("mobile/android/mach_commands.py"),
+        "gradle-install": MachCommandReference("mobile/android/mach_commands.py"),
         "mach-commands": MachCommandReference(
             "python/mach/mach/commands/commandinfo.py"
         ),
-        "mach-completion": MachCommandReference(
-            "python/mach/mach/commands/commandinfo.py"
-        ),
         "mach-debug-commands": MachCommandReference(
             "python/mach/mach/commands/commandinfo.py"
         ),
-        "marionette-test": MachCommandReference("testing/marionette/mach_commands.py"),
-        "mochitest": MachCommandReference("testing/mochitest/mach_commands.py"),
-        "mots": MachCommandReference("tools/mach_commands.py"),
-        "mozbuild-reference": MachCommandReference(
-            "python/mozbuild/mozbuild/frontend/mach_commands.py", "docs"
+        "mach-completion": MachCommandReference(
+            "python/mach/mach/commands/commandinfo.py"
         ),
-        "mozharness": MachCommandReference("testing/mozharness/mach_commands.py"),
-        "mozregression": MachCommandReference("tools/mach_commands.py"),
-        "node": MachCommandReference("tools/mach_commands.py"),
-        "npm": MachCommandReference("tools/mach_commands.py"),
-        "package": MachCommandReference("python/mozbuild/mozbuild/mach_commands.py"),
-        "package-multi-locale": MachCommandReference(
+        "settings": MachCommandReference("python/mach/mach/commands/settings.py"),
+        "python": MachCommandReference("python/mach_commands.py"),
+        "python-test": MachCommandReference("python/mach_commands.py"),
+        "bootstrap": MachCommandReference("python/mozboot/mozboot/mach_commands.py"),
+        "vcs-setup": MachCommandReference("python/mozboot/mozboot/mach_commands.py"),
+        "artifact": MachCommandReference(
+            "python/mozbuild/mozbuild/artifact_commands.py"
+        ),
+        "ide": MachCommandReference(
+            "python/mozbuild/mozbuild/backend/mach_commands.py"
+        ),
+        "build": MachCommandReference("python/mozbuild/mozbuild/build_commands.py"),
+        "configure": MachCommandReference("python/mozbuild/mozbuild/build_commands.py"),
+        "resource-usage": MachCommandReference(
+            "python/mozbuild/mozbuild/build_commands.py"
+        ),
+        "build-backend": MachCommandReference(
+            "python/mozbuild/mozbuild/build_commands.py"
+        ),
+        "clang-tidy": MachCommandReference(
+            "python/mozbuild/mozbuild/code_analysis/mach_commands.py"
+        ),
+        "static-analysis": MachCommandReference(
+            "python/mozbuild/mozbuild/code_analysis/mach_commands.py"
+        ),
+        "prettier-format": MachCommandReference(
+            "python/mozbuild/mozbuild/code_analysis/mach_commands.py"
+        ),
+        "clang-format": MachCommandReference(
+            "python/mozbuild/mozbuild/code_analysis/mach_commands.py"
+        ),
+        "compileflags": MachCommandReference(
+            "python/mozbuild/mozbuild/compilation/codecomplete.py"
+        ),
+        "mozbuild-reference": MachCommandReference(
+            "python/mozbuild/mozbuild/frontend/mach_commands.py"
+        ),
+        "file-info": MachCommandReference(
+            "python/mozbuild/mozbuild/frontend/mach_commands.py"
+        ),
+        "vendor": MachCommandReference(
+            "python/mozbuild/mozbuild/vendor/mach_commands.py"
+        ),
+        "watch": MachCommandReference("python/mozbuild/mozbuild/mach_commands.py"),
+        "cargo": MachCommandReference("python/mozbuild/mozbuild/mach_commands.py"),
+        "doctor": MachCommandReference("python/mozbuild/mozbuild/mach_commands.py"),
+        "clobber": MachCommandReference("python/mozbuild/mozbuild/mach_commands.py"),
+        "show-log": MachCommandReference("python/mozbuild/mozbuild/mach_commands.py"),
+        "warnings-summary": MachCommandReference(
             "python/mozbuild/mozbuild/mach_commands.py"
         ),
-        "pastebin": MachCommandReference("tools/mach_commands.py"),
-        "perf-data-review": MachCommandReference(
-            "toolkit/components/glean/build_scripts/mach_commands.py"
+        "warnings-list": MachCommandReference(
+            "python/mozbuild/mozbuild/mach_commands.py"
+        ),
+        "gtest": MachCommandReference("python/mozbuild/mozbuild/mach_commands.py"),
+        "package": MachCommandReference("python/mozbuild/mozbuild/mach_commands.py"),
+        "install": MachCommandReference("python/mozbuild/mozbuild/mach_commands.py"),
+        "run": MachCommandReference("python/mozbuild/mozbuild/mach_commands.py"),
+        "buildsymbols": MachCommandReference(
+            "python/mozbuild/mozbuild/mach_commands.py"
+        ),
+        "environment": MachCommandReference(
+            "python/mozbuild/mozbuild/mach_commands.py"
+        ),
+        "repackage": MachCommandReference("python/mozbuild/mozbuild/mach_commands.py"),
+        "package-multi-locale": MachCommandReference(
+            "python/mozbuild/mozbuild/mach_commands.py"
         ),
         "perftest": MachCommandReference(
             "python/mozperftest/mozperftest/mach_commands.py"
         ),
         "perftest-test": MachCommandReference(
-            "python/mozperftest/mozperftest/mach_commands.py", "perftest-test"
-        ),
-        "perftest-tools": MachCommandReference(
             "python/mozperftest/mozperftest/mach_commands.py"
         ),
-        "power": MachCommandReference("tools/power/mach_commands.py"),
-        "prettier-format": MachCommandReference(
-            "python/mozbuild/mozbuild/code_analysis/mach_commands.py"
-        ),
-        "puppeteer-test": MachCommandReference("remote/mach_commands.py"),
-        "python": MachCommandReference("python/mach_commands.py"),
-        "python-test": MachCommandReference("python/mach_commands.py", "python-test"),
-        "raptor": MachCommandReference("testing/raptor/mach_commands.py"),
-        "raptor-test": MachCommandReference("testing/raptor/mach_commands.py"),
-        "reftest": MachCommandReference("layout/tools/reftest/mach_commands.py"),
         "release": MachCommandReference(
             "python/mozrelease/mozrelease/mach_commands.py"
         ),
-        "release-history": MachCommandReference("taskcluster/mach_commands.py"),
         "remote": MachCommandReference("remote/mach_commands.py"),
-        "repackage": MachCommandReference("python/mozbuild/mozbuild/mach_commands.py"),
-        "resource-usage": MachCommandReference(
-            "python/mozbuild/mozbuild/build_commands.py", "build"
+        "puppeteer-test": MachCommandReference("remote/mach_commands.py"),
+        "generate-test-certs": MachCommandReference(
+            "security/manager/tools/mach_commands.py"
         ),
-        "run": MachCommandReference("python/mozbuild/mozbuild/mach_commands.py"),
-        "run-condprofile": MachCommandReference("testing/condprofile/mach_commands.py"),
-        "rusttests": MachCommandReference("testing/mach_commands.py"),
-        "settings": MachCommandReference("python/mach/mach/commands/settings.py"),
-        "show-log": MachCommandReference("python/mozbuild/mozbuild/mach_commands.py"),
-        "static-analysis": MachCommandReference(
-            "python/mozbuild/mozbuild/code_analysis/mach_commands.py"
-        ),
-        "storybook": MachCommandReference(
-            "browser/components/storybook/mach_commands.py"
-        ),
-        "talos-test": MachCommandReference("testing/talos/mach_commands.py"),
+        "taskgraph": MachCommandReference("taskcluster/mach_commands.py"),
+        "taskcluster-load-image": MachCommandReference("taskcluster/mach_commands.py"),
         "taskcluster-build-image": MachCommandReference("taskcluster/mach_commands.py"),
         "taskcluster-image-digest": MachCommandReference(
             "taskcluster/mach_commands.py"
         ),
-        "taskcluster-load-image": MachCommandReference("taskcluster/mach_commands.py"),
-        "taskgraph": MachCommandReference("taskcluster/mach_commands.py"),
+        "release-history": MachCommandReference("taskcluster/mach_commands.py"),
+        "awsy-test": MachCommandReference("testing/awsy/mach_commands.py"),
+        "fetch-condprofile": MachCommandReference(
+            "testing/condprofile/mach_commands.py"
+        ),
+        "run-condprofile": MachCommandReference("testing/condprofile/mach_commands.py"),
+        "firefox-ui-functional": MachCommandReference(
+            "testing/firefox-ui/mach_commands.py"
+        ),
+        "geckodriver": MachCommandReference("testing/geckodriver/mach_commands.py"),
+        "addtest": MachCommandReference("testing/mach_commands.py"),
+        "test": MachCommandReference("testing/mach_commands.py"),
+        "cppunittest": MachCommandReference("testing/mach_commands.py"),
+        "jstests": MachCommandReference("testing/mach_commands.py"),
+        "jit-test": MachCommandReference("testing/mach_commands.py"),
+        "jsapi-tests": MachCommandReference("testing/mach_commands.py"),
+        "jsshell-bench": MachCommandReference("testing/mach_commands.py"),
+        "cramtest": MachCommandReference("testing/mach_commands.py"),
+        "test-info": MachCommandReference("testing/mach_commands.py"),
+        "rusttests": MachCommandReference("testing/mach_commands.py"),
+        "fluent-migration-test": MachCommandReference("testing/mach_commands.py"),
+        "marionette-test": MachCommandReference("testing/marionette/mach_commands.py"),
+        "mochitest": MachCommandReference("testing/mochitest/mach_commands.py"),
+        "geckoview-junit": MachCommandReference("testing/mochitest/mach_commands.py"),
+        "mozharness": MachCommandReference("testing/mozharness/mach_commands.py"),
+        "raptor": MachCommandReference("testing/raptor/mach_commands.py"),
+        "raptor-test": MachCommandReference("testing/raptor/mach_commands.py"),
+        "talos-test": MachCommandReference("testing/talos/mach_commands.py"),
+        "tps-build": MachCommandReference("testing/tps/mach_commands.py"),
+        "web-platform-tests": MachCommandReference(
+            "testing/web-platform/mach_commands.py"
+        ),
+        "wpt": MachCommandReference("testing/web-platform/mach_commands.py"),
+        "web-platform-tests-update": MachCommandReference(
+            "testing/web-platform/mach_commands.py"
+        ),
+        "wpt-update": MachCommandReference("testing/web-platform/mach_commands.py"),
+        "wpt-manifest-update": MachCommandReference(
+            "testing/web-platform/mach_commands.py"
+        ),
+        "wpt-serve": MachCommandReference("testing/web-platform/mach_commands.py"),
+        "wpt-metadata-summary": MachCommandReference(
+            "testing/web-platform/mach_commands.py"
+        ),
+        "wpt-metadata-merge": MachCommandReference(
+            "testing/web-platform/mach_commands.py"
+        ),
+        "wpt-unittest": MachCommandReference("testing/web-platform/mach_commands.py"),
+        "wpt-test-paths": MachCommandReference("testing/web-platform/mach_commands.py"),
+        "wpt-fission-regressions": MachCommandReference(
+            "testing/web-platform/mach_commands.py"
+        ),
+        "xpcshell-test": MachCommandReference("testing/xpcshell/mach_commands.py"),
         "telemetry-tests-client": MachCommandReference(
             "toolkit/components/telemetry/tests/marionette/mach_commands.py"
         ),
-        "test": MachCommandReference("testing/mach_commands.py"),
-        "test-info": MachCommandReference("testing/mach_commands.py"),
-        "test-interventions": MachCommandReference(
-            "testing/webcompat/mach_commands.py", "webcompat"
+        "data-review": MachCommandReference(
+            "toolkit/components/glean/build_scripts/mach_commands.py"
         ),
-        "tps-build": MachCommandReference("testing/tps/mach_commands.py"),
-        "try": MachCommandReference("tools/tryselect/mach_commands.py"),
-        "uniffi": MachCommandReference(
-            "toolkit/components/uniffi-bindgen-gecko-js/mach_commands.py"
-        ),
-        "update-glean": MachCommandReference(
+        "perf-data-review": MachCommandReference(
             "toolkit/components/glean/build_scripts/mach_commands.py"
         ),
         "update-glean-tags": MachCommandReference(
             "toolkit/components/glean/build_scripts/mach_commands.py"
         ),
-        "valgrind-test": MachCommandReference("build/valgrind/mach_commands.py"),
-        "vcs-setup": MachCommandReference(
-            "python/mozboot/mozboot/mach_commands.py", "build"
+        "update-glean": MachCommandReference(
+            "toolkit/components/glean/build_scripts/mach_commands.py"
         ),
-        "vendor": MachCommandReference(
-            "python/mozbuild/mozbuild/vendor/mach_commands.py", "vendor"
+        "browsertime": MachCommandReference("tools/browsertime/mach_commands.py"),
+        "compare-locales": MachCommandReference(
+            "tools/compare-locales/mach_commands.py"
         ),
-        "warnings-list": MachCommandReference(
-            "python/mozbuild/mozbuild/mach_commands.py"
-        ),
-        "warnings-summary": MachCommandReference(
-            "python/mozbuild/mozbuild/mach_commands.py"
-        ),
-        "watch": MachCommandReference(
-            "python/mozbuild/mozbuild/mach_commands.py", "watch"
-        ),
-        "web-platform-tests": MachCommandReference(
-            "testing/web-platform/mach_commands.py", "wpt"
-        ),
-        "web-platform-tests-update": MachCommandReference(
-            "testing/web-platform/mach_commands.py", "wpt"
-        ),
-        "webidl-example": MachCommandReference("dom/bindings/mach_commands.py"),
-        "webidl-parser-test": MachCommandReference("dom/bindings/mach_commands.py"),
-        "wpt": MachCommandReference("testing/web-platform/mach_commands.py", "wpt"),
-        "wpt-fetch-logs": MachCommandReference(
-            "testing/web-platform/mach_commands.py", "wpt-interop"
-        ),
-        "wpt-fission-regressions": MachCommandReference(
-            "testing/web-platform/mach_commands.py", "wpt"
-        ),
-        "wpt-interop-score": MachCommandReference(
-            "testing/web-platform/mach_commands.py", "wpt-interop"
-        ),
-        "wpt-manifest-update": MachCommandReference(
-            "testing/web-platform/mach_commands.py", "wpt"
-        ),
-        "wpt-metadata-merge": MachCommandReference(
-            "testing/web-platform/mach_commands.py", "wpt"
-        ),
-        "wpt-metadata-summary": MachCommandReference(
-            "testing/web-platform/mach_commands.py", "wpt"
-        ),
-        "wpt-serve": MachCommandReference(
-            "testing/web-platform/mach_commands.py", "wpt"
-        ),
-        "wpt-test-paths": MachCommandReference(
-            "testing/web-platform/mach_commands.py", "wpt"
-        ),
-        "wpt-unittest": MachCommandReference(
-            "testing/web-platform/mach_commands.py", "wpt"
-        ),
-        "wpt-update": MachCommandReference(
-            "testing/web-platform/mach_commands.py", "wpt"
+        "l10n-cross-channel": MachCommandReference("tools/lint/mach_commands.py"),
+        "busted": MachCommandReference("tools/mach_commands.py"),
+        "pastebin": MachCommandReference("tools/mach_commands.py"),
+        "mozregression": MachCommandReference("tools/mach_commands.py"),
+        "node": MachCommandReference("tools/mach_commands.py"),
+        "npm": MachCommandReference("tools/mach_commands.py"),
+        "logspam": MachCommandReference("tools/mach_commands.py"),
+        "doc": MachCommandReference("tools/moztreedocs/mach_commands.py"),
+        "install-moz-phab": MachCommandReference("tools/phabricator/mach_commands.py"),
+        "power": MachCommandReference("tools/power/mach_commands.py"),
+        "try": MachCommandReference("tools/tryselect/mach_commands.py"),
+        "import-pr": MachCommandReference("tools/vcs/mach_commands.py"),
+        "test-interventions": MachCommandReference(
+            "testing/webcompat/mach_commands.py"
         ),
+        "esmify": MachCommandReference("tools/esmify/mach_commands.py"),
         "xpcshell": MachCommandReference("js/xpconnect/mach_commands.py"),
-        "xpcshell-test": MachCommandReference("testing/xpcshell/mach_commands.py"),
+        "uniffi": MachCommandReference(
+            "toolkit/components/uniffi-bindgen-gecko-js/mach_commands.py"
+        ),
+        "storybook": MachCommandReference(
+            "browser/components/storybook/mach_commands.py"
+        ),
+        "widgets": MachCommandReference("toolkit/content/widgets/mach_commands.py"),
     }
 
-    command_name = next((x for x in args if not x.startswith("-")), None)
-    command_site_manager = None
-
-    # the 'clobber' command needs to run in the 'mach' venv, so we
-    # don't want to activate any other virtualenv for it.
-    if command_name != "clobber":
-        site_name = getattr(MACH_COMMANDS.get(command_name), "site_name", "common")
-
-        from mach.site import CommandSiteManager
-
-        command_site_manager = CommandSiteManager.from_environment(
-            topsrcdir,
-            lambda: os.path.normpath(get_state_dir(True, topsrcdir=topsrcdir)),
-            site_name,
-            get_virtualenv_base_dir(topsrcdir),
-        )
-
-        command_site_manager.activate()
-
     # Set a reasonable limit to the number of open files.
     #
     # Some linux systems set `ulimit -n` to a very high number, which works
@@ -541,7 +488,7 @@ def initialize(topsrcdir, args=()):
     if "MACH_MAIN_PID" not in os.environ:
         setenv("MACH_MAIN_PID", str(os.getpid()))
 
-    driver = mach.main.Mach(os.getcwd(), command_site_manager)
+    driver = mach.main.Mach(os.getcwd())
     driver.populate_context_handler = populate_context
 
     if not driver.settings_paths:
@@ -562,14 +509,7 @@ def initialize(topsrcdir, args=()):
         ) or os.path.exists(os.path.join(topsrcdir, "INSTALL"))
     else:
         missing_ok = ()
-    if command_name not in MACH_COMMANDS:
-        command_modules_to_load = MACH_COMMANDS
-    else:
-        command_modules_to_load = {command_name: MACH_COMMANDS[command_name]}
-
-    driver.load_commands_from_spec(
-        command_modules_to_load, topsrcdir, missing_ok=missing_ok
-    )
+    driver.load_commands_from_spec(MACH_COMMANDS, topsrcdir, missing_ok=missing_ok)
     return driver
 
 
diff --git a/mach b/mach
index a62db70b13a5..cc5e25b7aa36 100755
--- a/mach
+++ b/mach
@@ -13,17 +13,17 @@ MIN_PYTHON_VERSION = (3, 7)
 MAX_PYTHON_VERSION_TO_CONSIDER = (3, 11)
 
 
-def load_mach(dir_path, mach_path, args):
+def load_mach(dir_path, mach_path):
     # Defer import of "importlib.util" until after Python version check has happened
     # so that Python 2 usages fail gracefully.
     import importlib.util
     spec = importlib.util.spec_from_file_location('mach_initialize', mach_path)
     mach_initialize = importlib.util.module_from_spec(spec)
     spec.loader.exec_module(mach_initialize)
-    return mach_initialize.initialize(dir_path, args)
+    return mach_initialize.initialize(dir_path)
 
 
-def check_and_get_mach(dir_path, args):
+def check_and_get_mach(dir_path):
     initialize_paths = (
         # Run Thunderbird's mach_initialize.py if it exists
         'comm/build/mach_initialize.py',
@@ -34,7 +34,7 @@ def check_and_get_mach(dir_path, args):
     for initialize_path in initialize_paths:
         mach_path = os.path.join(dir_path, initialize_path)
         if os.path.isfile(mach_path):
-            return load_mach(dir_path, mach_path, args)
+            return load_mach(dir_path, mach_path)
     return None
 
 
@@ -114,7 +114,7 @@ def main(args):
     # https://github.com/python/cpython/pull/9516
     os.environ.pop("__PYVENV_LAUNCHER__", None)
 
-    mach = check_and_get_mach(os.path.dirname(os.path.realpath(__file__)), args)
+    mach = check_and_get_mach(os.path.dirname(os.path.realpath(__file__)))
     if not mach:
         print('Could not run mach: No mach source directory found.')
         sys.exit(1)
diff --git a/python/mach/mach/main.py b/python/mach/mach/main.py
index 1b4782367ad3..79fcb8e8ad17 100644
--- a/python/mach/mach/main.py
+++ b/python/mach/mach/main.py
@@ -16,9 +16,7 @@ import traceback
 import uuid
 from collections.abc import Iterable
 from pathlib import Path
-from typing import Dict, List, Optional, Union
-
-from mach.site import CommandSiteManager
+from typing import Dict, List, Union
 
 from .base import (
     CommandContext,
@@ -182,13 +180,8 @@ class MachCommandReference:
 
     module: Path
 
-    def __init__(
-        self,
-        module: Union[str, Path],
-        command_site_name: Optional[str] = None,
-    ):
+    def __init__(self, module: Union[str, Path]):
         self.module = Path(module)
-        self.site_name = command_site_name if command_site_name else "common"
 
 
 class Mach(object):
@@ -233,9 +226,7 @@ To see more help for a specific command, run:
   %(prog)s help <command>
 """
 
-    def __init__(
-        self, cwd: str, command_site_manager: Optional[CommandSiteManager] = None
-    ):
+    def __init__(self, cwd: str):
         assert Path(cwd).is_dir()
 
         self.cwd = cwd
@@ -243,7 +234,6 @@ To see more help for a specific command, run:
         self.logger = logging.getLogger(__name__)
         self.settings = ConfigSettings()
         self.settings_paths = []
-        self.command_site_manager = command_site_manager
 
         if "MACHRC" in os.environ:
             self.settings_paths.append(os.environ["MACHRC"])
@@ -529,7 +519,6 @@ To see more help for a specific command, run:
             return Registrar._run_command_handler(
                 handler,
                 context,
-                self.command_site_manager,
                 debug_command=args.debug_command,
                 profile_command=args.profile_command,
                 **vars(args.command_args),
diff --git a/python/mach/mach/registrar.py b/python/mach/mach/registrar.py
index e7738af81c31..75481596f4b4 100644
--- a/python/mach/mach/registrar.py
+++ b/python/mach/mach/registrar.py
@@ -86,13 +86,7 @@ class MachRegistrar(object):
         return fail_conditions
 
     def _run_command_handler(
-        self,
-        handler,
-        context,
-        command_site_manager=None,
-        debug_command=False,
-        profile_command=False,
-        **kwargs,
+        self, handler, context, debug_command=False, profile_command=False, **kwargs
     ):
         instance = MachRegistrar._instance(handler, context, **kwargs)
         fail_conditions = MachRegistrar._fail_conditions(handler, instance)
@@ -105,10 +99,7 @@ class MachRegistrar(object):
         self.command_depth += 1
         fn = handler.func
         if handler.virtualenv_name:
-            if command_site_manager:
-                instance.virtualenv_manager = command_site_manager
-            else:
-                instance.activate_virtualenv()
+            instance.activate_virtualenv()
 
         profile = None
         if profile_command:
diff --git a/python/mozbuild/mozbuild/artifact_commands.py b/python/mozbuild/mozbuild/artifact_commands.py
index d5abf1a0998d..12184ce0d984 100644
--- a/python/mozbuild/mozbuild/artifact_commands.py
+++ b/python/mozbuild/mozbuild/artifact_commands.py
@@ -132,11 +132,7 @@ def _make_artifacts(
     return artifacts
 
 
-@ArtifactSubCommand(
-    "artifact",
-    "install",
-    "Install a good pre-built artifact.",
-)
+@ArtifactSubCommand("artifact", "install", "Install a good pre-built artifact.")
 @CommandArgument(
     "source",
     metavar="SRC",
@@ -204,10 +200,7 @@ def artifact_clear_cache(command_context, tree=None, job=None, verbose=False):
     return 0
 
 
-@SubCommand(
-    "artifact",
-    "toolchain",
-)
+@SubCommand("artifact", "toolchain")
 @CommandArgument("--verbose", "-v", action="store_true", help="Print verbose output.")
 @CommandArgument(
     "--cache-dir",
@@ -271,10 +264,6 @@ def artifact_toolchain(
     """Download, cache and install pre-built toolchains."""
     import time
 
-    # As a result of the selective module loading changes, this import has to be
-    # done here. It is not explicitly used, but it has an implicit side-effect
-    # (bringing in TASKCLUSTER_ROOT_URL) which is necessary.
-    import gecko_taskgraph.main  # noqa: F401
     import redo
     import requests
     from taskgraph.util.taskcluster import get_artifact_url
diff --git a/python/mozbuild/mozbuild/base.py b/python/mozbuild/mozbuild/base.py
index 3f5a6242f838..8dc9f90dbf64 100644
--- a/python/mozbuild/mozbuild/base.py
+++ b/python/mozbuild/mozbuild/base.py
@@ -268,10 +268,6 @@ class MozbuildObject(ProcessExecutionMixin):
 
         return self._virtualenv_manager
 
-    @virtualenv_manager.setter
-    def virtualenv_manager(self, command_site_manager):
-        self._virtualenv_manager = command_site_manager
-
     @staticmethod
     @memoize
     def get_base_mozconfig_info(topsrcdir, path, env_mozconfig):
diff --git a/python/mozbuild/mozbuild/mach_commands.py b/python/mozbuild/mozbuild/mach_commands.py
index 370b9888be7e..0c388f198bfc 100644
--- a/python/mozbuild/mozbuild/mach_commands.py
+++ b/python/mozbuild/mozbuild/mach_commands.py
@@ -29,6 +29,7 @@ from mach.decorators import (
     SettingsProvider,
     SubCommand,
 )
+from voluptuous import All, Boolean, Required, Schema
 
 import mozbuild.settings  # noqa need @SettingsProvider hook to execute
 from mozbuild.base import (
@@ -112,8 +113,6 @@ To do so, add the corresponding file in <mozilla-root-dir>/build/cargo, followin
 
 
 def _cargo_config_yaml_schema():
-    from voluptuous import All, Boolean, Required, Schema
-
     def starts_with_cargo(s):
         if s.startswith("cargo-"):
             return s
diff --git a/python/sites/build.txt b/python/sites/build.txt
index 691a9a2f6e61..4e6f6c51d9ad 100644
--- a/python/sites/build.txt
+++ b/python/sites/build.txt
@@ -1,51 +1 @@
 pth:third_party/python/vsdownload
-vendored:testing/web-platform/tests/tools/third_party/h2
-vendored:testing/web-platform/tests/tools/third_party/hpack
-vendored:testing/web-platform/tests/tools/third_party/html5lib
-vendored:testing/web-platform/tests/tools/third_party/hyperframe
-vendored:testing/web-platform/tests/tools/third_party/pywebsocket3
-vendored:testing/web-platform/tests/tools/third_party/webencodings
-vendored:testing/web-platform/tests/tools/wptrunner
-vendored:testing/web-platform/tests/tools/wptserve
-vendored:third_party/python/Jinja2
-vendored:third_party/python/PyYAML/lib3/
-vendored:third_party/python/aiohttp
-vendored:third_party/python/appdirs
-vendored:third_party/python/async_timeout
-vendored:third_party/python/chardet
-vendored:third_party/python/compare_locales
-vendored:third_party/python/diskcache
-vendored:third_party/python/dlmanager
-vendored:third_party/python/ecdsa
-vendored:third_party/python/fluent.migrate
-vendored:third_party/python/fluent.syntax
-vendored:third_party/python/giturlparse
-vendored:third_party/python/glean_parser
-vendored:third_party/python/gyp/pylib
-vendored:third_party/python/importlib_metadata
-vendored:third_party/python/importlib_resources
-vendored:third_party/python/json-e
-vendored:third_party/python/jsonschema
-vendored:third_party/python/mohawk
-vendored:third_party/python/mozilla_repo_urls
-vendored:third_party/python/multidict
-vendored:third_party/python/pathspec
-vendored:third_party/python/pkgutil_resolve_name
-vendored:third_party/python/ply
-vendored:third_party/python/pyasn1
-vendored:third_party/python/pyasn1_modules
-vendored:third_party/python/pylru
-vendored:third_party/python/pyrsistent
-vendored:third_party/python/redo
-vendored:third_party/python/requests_unixsocket
-vendored:third_party/python/rsa
-vendored:third_party/python/slugid
-vendored:third_party/python/taskcluster
-vendored:third_party/python/taskcluster_taskgraph
-vendored:third_party/python/taskcluster_urls
-vendored:third_party/python/toml
-vendored:third_party/python/typing_extensions
-vendored:third_party/python/voluptuous
-vendored:third_party/python/yamllint
-vendored:third_party/python/yarl
-vendored:third_party/python/zipp
diff --git a/python/sites/common.txt b/python/sites/common.txt
index e693cd06ba9f..8b137891791f 100644
--- a/python/sites/common.txt
+++ b/python/sites/common.txt
@@ -1,56 +1 @@
-vendored:testing/web-platform/tests/tools/third_party/h2
-vendored:testing/web-platform/tests/tools/third_party/hpack
-vendored:testing/web-platform/tests/tools/third_party/html5lib
-vendored:testing/web-platform/tests/tools/third_party/hyperframe
-vendored:testing/web-platform/tests/tools/third_party/pywebsocket3
-vendored:testing/web-platform/tests/tools/third_party/webencodings
-vendored:testing/web-platform/tests/tools/wptrunner
-vendored:testing/web-platform/tests/tools/wptserve
-vendored:third_party/python/MarkupSafe/src
-vendored:third_party/python/PyYAML/lib3/
-vendored:third_party/python/aiohttp
-vendored:third_party/python/appdirs
-vendored:third_party/python/async_timeout
-vendored:third_party/python/cbor2
-vendored:third_party/python/chardet
-vendored:third_party/python/compare_locales
-vendored:third_party/python/cookies
-vendored:third_party/python/cram
-vendored:third_party/python/diskcache
-vendored:third_party/python/dlmanager
-vendored:third_party/python/ecdsa
-vendored:third_party/python/esprima
-vendored:third_party/python/fluent.migrate
-vendored:third_party/python/fluent.syntax
-vendored:third_party/python/giturlparse
-vendored:third_party/python/glean_parser
-vendored:third_party/python/gyp/pylib
-vendored:third_party/python/importlib_metadata
-vendored:third_party/python/importlib_resources
-vendored:third_party/python/json-e
-vendored:third_party/python/jsonschema
-vendored:third_party/python/mohawk
-vendored:third_party/python/mozilla_repo_urls
-vendored:third_party/python/multidict
-vendored:third_party/python/pathspec
-vendored:third_party/python/pkgutil_resolve_name
-vendored:third_party/python/ply
-vendored:third_party/python/pyasn1
-vendored:third_party/python/pyasn1_modules
-vendored:third_party/python/pylru
-vendored:third_party/python/pyparsing
-vendored:third_party/python/pyrsistent
-vendored:third_party/python/redo
-vendored:third_party/python/requests_unixsocket
-vendored:third_party/python/responses
-vendored:third_party/python/rsa
-vendored:third_party/python/slugid
-vendored:third_party/python/taskcluster
-vendored:third_party/python/taskcluster_taskgraph
-vendored:third_party/python/taskcluster_urls
-vendored:third_party/python/toml
-vendored:third_party/python/typing_extensions
-vendored:third_party/python/voluptuous
-vendored:third_party/python/yamllint
-vendored:third_party/python/yarl
-vendored:third_party/python/zipp
+
diff --git a/python/sites/docs.txt b/python/sites/docs.txt
index 60820c4dd837..b6b9cd63e883 100644
--- a/python/sites/docs.txt
+++ b/python/sites/docs.txt
@@ -4,14 +4,19 @@ pypi:Babel==2.12.1
 pypi:backports-abc==0.5
 pypi:boto3==1.26.80
 pypi:botocore==1.29.80
+pypi:colorama==0.4.5
 pypi:commonmark==0.9.1
 pypi:docutils==0.17.1
 pypi:fluent.pygments==1.0
+pypi:fluent.syntax==0.19.0
 pypi:idna==2.10
 pypi:imagesize==1.4.1
+pypi:importlib-resources==5.12.0
 pypi:jmespath==1.0.1
+pypi:jsonschema==4.17.3
 pypi:livereload==2.6.3
 pypi:Markdown==3.4.3
+pypi:MarkupSafe==2.0.1
 pypi:mock==5.0.1
 pypi:mots==0.8.0
 pypi:myst-parser==1.0
@@ -20,6 +25,7 @@ pypi:parsimonious==0.10.0
 pypi:pyasn1==0.4.8
 pypi:pyasn1-modules==0.2.8
 pypi:Pygments==2.14.0
+pypi:pyparsing==2.4.7
 # for autodoc
 pypi:pytest==7.2.1
 pypi:python-dateutil==2.8.2
@@ -27,6 +33,7 @@ pypi:python-frontmatter==1.0.0
 pypi:pytz==2022.7.1
 # for autodoc
 pypi:pywatchman==1.4.1
+pypi:redo==2.0.3
 pypi:s3transfer==0.6.0
 pypi:scandir==1.10.0
 pypi:singledispatch==4.0.0
@@ -46,35 +53,16 @@ pypi:sphinxcontrib-qthelp==1.0.3
 pypi:sphinxcontrib-serializinghtml==1.1.5
 pypi:tornado==6.0.4
 vendored:third_party/python/Jinja2
-vendored:third_party/python/MarkupSafe/src
-vendored:third_party/python/PyYAML/lib3/
-vendored:third_party/python/aiohttp
-vendored:third_party/python/appdirs
-vendored:third_party/python/async_timeout
 vendored:third_party/python/certifi
 vendored:third_party/python/chardet
-vendored:third_party/python/fluent.syntax
-vendored:third_party/python/giturlparse
 vendored:third_party/python/importlib_metadata
 vendored:third_party/python/importlib_resources
-vendored:third_party/python/json-e
 vendored:third_party/python/jsonschema
-vendored:third_party/python/mohawk
-vendored:third_party/python/mozilla_repo_urls
 vendored:third_party/python/packaging
 vendored:third_party/python/pkgutil_resolve_name
-vendored:third_party/python/pyparsing
-vendored:third_party/python/redo
 vendored:third_party/python/requests
-vendored:third_party/python/requests_unixsocket
 vendored:third_party/python/rsa
 vendored:third_party/python/sentry_sdk
 vendored:third_party/python/six
-vendored:third_party/python/slugid
-vendored:third_party/python/taskcluster
-vendored:third_party/python/taskcluster_taskgraph
-vendored:third_party/python/taskcluster_urls
-vendored:third_party/python/toml
 vendored:third_party/python/urllib3
-vendored:third_party/python/voluptuous
 vendored:third_party/python/zipp
diff --git a/python/sites/lint.txt b/python/sites/lint.txt
index 5f79a4c5495d..139597f9cb07 100644
--- a/python/sites/lint.txt
+++ b/python/sites/lint.txt
@@ -1,28 +1,2 @@
-vendored:third_party/python/PyYAML/lib3/
-vendored:third_party/python/aiohttp
-vendored:third_party/python/appdirs
-vendored:third_party/python/async_timeout
-vendored:third_party/python/chardet
-vendored:third_party/python/compare_locales
-vendored:third_party/python/esprima
-vendored:third_party/python/fluent.syntax
-vendored:third_party/python/giturlparse
-vendored:third_party/python/json-e
-vendored:third_party/python/jsonschema
-vendored:third_party/python/mohawk
-vendored:third_party/python/mozilla_repo_urls
-vendored:third_party/python/multidict
-vendored:third_party/python/pathspec
-vendored:third_party/python/pyparsing
-vendored:third_party/python/pyrsistent
-vendored:third_party/python/redo
-vendored:third_party/python/requests_unixsocket
-vendored:third_party/python/slugid
-vendored:third_party/python/taskcluster
-vendored:third_party/python/taskcluster_taskgraph
-vendored:third_party/python/taskcluster_urls
-vendored:third_party/python/toml
-vendored:third_party/python/typing_extensions
-vendored:third_party/python/voluptuous
-vendored:third_party/python/yamllint
-vendored:third_party/python/yarl
+
+
diff --git a/python/sites/mach.txt b/python/sites/mach.txt
index 66d342597db4..456c45ae99b2 100644
--- a/python/sites/mach.txt
+++ b/python/sites/mach.txt
@@ -26,8 +26,8 @@ pth:testing/mozbase/mozcrash
 pth:testing/mozbase/mozdebug
 pth:testing/mozbase/mozdevice
 pth:testing/mozbase/mozfile
-pth:testing/mozbase/mozgeckoprofiler
 pth:testing/mozbase/mozhttpd
+pth:testing/mozbase/mozgeckoprofiler
 pth:testing/mozbase/mozinfo
 pth:testing/mozbase/mozinstall
 pth:testing/mozbase/mozleak
@@ -38,50 +38,103 @@ pth:testing/mozbase/mozprocess
 pth:testing/mozbase/mozprofile
 pth:testing/mozbase/mozproxy
 pth:testing/mozbase/mozrunner
-pth:testing/mozbase/mozscreenshot
 pth:testing/mozbase/mozserve
 pth:testing/mozbase/mozsystemmonitor
+pth:testing/mozbase/mozscreenshot
 pth:testing/mozbase/moztest
 pth:testing/mozbase/mozversion
 pth:testing/mozharness
 pth:testing/raptor
 pth:testing/talos
 pth:testing/web-platform
+vendored:testing/web-platform/tests/tools/third_party/h2
+vendored:testing/web-platform/tests/tools/third_party/hpack
+vendored:testing/web-platform/tests/tools/third_party/html5lib
+vendored:testing/web-platform/tests/tools/third_party/hyperframe
+vendored:testing/web-platform/tests/tools/third_party/pywebsocket3
+vendored:testing/web-platform/tests/tools/third_party/webencodings
+vendored:testing/web-platform/tests/tools/wptserve
+vendored:testing/web-platform/tests/tools/wptrunner
 pth:testing/xpcshell
+vendored:third_party/python/aiohttp
+vendored:third_party/python/ansicon
+vendored:third_party/python/appdirs
+vendored:third_party/python/async_timeout
+vendored:third_party/python/attrs
+vendored:third_party/python/blessed
+vendored:third_party/python/cbor2
+vendored:third_party/python/certifi
+vendored:third_party/python/chardet
+vendored:third_party/python/click
+vendored:third_party/python/colorama
+vendored:third_party/python/compare_locales
+vendored:third_party/python/cookies
+vendored:third_party/python/cram
+vendored:third_party/python/diskcache
+vendored:third_party/python/distro
+vendored:third_party/python/dlmanager
+vendored:third_party/python/ecdsa
+vendored:third_party/python/esprima
+vendored:third_party/python/fluent.migrate
+vendored:third_party/python/fluent.syntax
+vendored:third_party/python/giturlparse
+vendored:third_party/python/glean_parser
+vendored:third_party/python/gyp/pylib
+vendored:third_party/python/idna
+vendored:third_party/python/importlib_metadata
+vendored:third_party/python/importlib_resources
+vendored:third_party/python/Jinja2
+vendored:third_party/python/jinxed
+vendored:third_party/python/jsmin
+vendored:third_party/python/json-e
+vendored:third_party/python/jsonschema
+vendored:third_party/python/looseversion
+vendored:third_party/python/MarkupSafe/src
+vendored:third_party/python/mohawk
+vendored:third_party/python/mozilla_repo_urls
+vendored:third_party/python/mozilla_version
+vendored:third_party/python/multidict
+vendored:third_party/python/packaging
+vendored:third_party/python/pathspec
+vendored:third_party/python/pip
+vendored:third_party/python/pip_tools
+vendored:third_party/python/pkgutil_resolve_name
+vendored:third_party/python/ply
+vendored:third_party/python/pyasn1
+vendored:third_party/python/pyasn1_modules
+vendored:third_party/python/pylru
+vendored:third_party/python/pyparsing
+vendored:third_party/python/pyrsistent
+vendored:third_party/python/python-hglib
+vendored:third_party/python/PyYAML/lib3/
+vendored:third_party/python/redo
+vendored:third_party/python/requests
+vendored:third_party/python/requests_unixsocket
+vendored:third_party/python/responses
+vendored:third_party/python/rsa
+vendored:third_party/python/setuptools
+vendored:third_party/python/sentry_sdk
+vendored:third_party/python/six
+vendored:third_party/python/slugid
+vendored:third_party/python/taskcluster
+vendored:third_party/python/taskcluster_taskgraph
+vendored:third_party/python/taskcluster_urls
+vendored:third_party/python/toml
+vendored:third_party/python/tqdm
+vendored:third_party/python/typing_extensions
+vendored:third_party/python/urllib3
+vendored:third_party/python/voluptuous
+vendored:third_party/python/wcwidth
+vendored:third_party/python/wheel
+vendored:third_party/python/yamllint
+vendored:third_party/python/yarl
+vendored:third_party/python/zipp
 pth:toolkit/components/telemetry/tests/marionette/harness
 pth:tools
 pth:tools/moztreedocs
 pth:xpcom/ds/tools
 pth:xpcom/geckoprocesstypes_generator
 pth:xpcom/idl-parser
-vendored:third_party/python/Jinja2
-vendored:third_party/python/MarkupSafe/src
-vendored:third_party/python/ansicon
-vendored:third_party/python/attrs
-vendored:third_party/python/blessed
-vendored:third_party/python/certifi
-vendored:third_party/python/chardet
-vendored:third_party/python/click
-vendored:third_party/python/colorama
-vendored:third_party/python/distro
-vendored:third_party/python/idna
-vendored:third_party/python/jinxed
-vendored:third_party/python/jsmin
-vendored:third_party/python/looseversion
-vendored:third_party/python/mozilla_version
-vendored:third_party/python/packaging
-vendored:third_party/python/pip
-vendored:third_party/python/pip_tools
-vendored:third_party/python/pyparsing
-vendored:third_party/python/python-hglib
-vendored:third_party/python/requests
-vendored:third_party/python/sentry_sdk
-vendored:third_party/python/setuptools
-vendored:third_party/python/six
-vendored:third_party/python/tqdm
-vendored:third_party/python/urllib3
-vendored:third_party/python/wcwidth
-vendored:third_party/python/wheel
 # glean-sdk may not be installable if a wheel isn't available
 # and it has to be built from source.
 pypi-optional:glean-sdk==53.0.0:telemetry will not be collected
diff --git a/python/sites/perftest-test.txt b/python/sites/perftest-test.txt
index ec5c652eb848..f457c8c66734 100644
--- a/python/sites/perftest-test.txt
+++ b/python/sites/perftest-test.txt
@@ -1,10 +1,2 @@
 pypi:pytest==7.0.1
 pypi:coverage==5.1
-vendored:third_party/python/PyYAML/lib3/
-vendored:third_party/python/dlmanager
-vendored:third_party/python/esprima
-vendored:third_party/python/importlib_resources
-vendored:third_party/python/jsonschema
-vendored:third_party/python/pyrsistent
-vendored:third_party/python/redo
-vendored:third_party/python/responses
\ No newline at end of file
diff --git a/python/sites/python-test.txt b/python/sites/python-test.txt
index 87d7e6dbe694..74889365a22b 100644
--- a/python/sites/python-test.txt
+++ b/python/sites/python-test.txt
@@ -1,57 +1 @@
 pypi:pytest==7.0.1
-vendored:testing/web-platform/tests/tools/third_party/h2
-vendored:testing/web-platform/tests/tools/third_party/hpack
-vendored:testing/web-platform/tests/tools/third_party/html5lib
-vendored:testing/web-platform/tests/tools/third_party/hyperframe
-vendored:testing/web-platform/tests/tools/third_party/pywebsocket3
-vendored:testing/web-platform/tests/tools/third_party/webencodings
-vendored:testing/web-platform/tests/tools/wptrunner
-vendored:testing/web-platform/tests/tools/wptserve
-vendored:third_party/python/MarkupSafe/src
-vendored:third_party/python/PyYAML/lib3/
-vendored:third_party/python/aiohttp
-vendored:third_party/python/appdirs
-vendored:third_party/python/async_timeout
-vendored:third_party/python/cbor2
-vendored:third_party/python/chardet
-vendored:third_party/python/compare_locales
-vendored:third_party/python/cookies
-vendored:third_party/python/cram
-vendored:third_party/python/diskcache
-vendored:third_party/python/dlmanager
-vendored:third_party/python/ecdsa
-vendored:third_party/python/esprima
-vendored:third_party/python/fluent.migrate
-vendored:third_party/python/fluent.syntax
-vendored:third_party/python/giturlparse
-vendored:third_party/python/glean_parser
-vendored:third_party/python/gyp/pylib
-vendored:third_party/python/importlib_metadata
-vendored:third_party/python/importlib_resources
-vendored:third_party/python/json-e
-vendored:third_party/python/jsonschema
-vendored:third_party/python/mohawk
-vendored:third_party/python/mozilla_repo_urls
-vendored:third_party/python/multidict
-vendored:third_party/python/pathspec
-vendored:third_party/python/pkgutil_resolve_name
-vendored:third_party/python/ply
-vendored:third_party/python/pyasn1
-vendored:third_party/python/pyasn1_modules
-vendored:third_party/python/pylru
-vendored:third_party/python/pyparsing
-vendored:third_party/python/pyrsistent
-vendored:third_party/python/redo
-vendored:third_party/python/requests_unixsocket
-vendored:third_party/python/responses
-vendored:third_party/python/rsa
-vendored:third_party/python/slugid
-vendored:third_party/python/taskcluster
-vendored:third_party/python/taskcluster_taskgraph
-vendored:third_party/python/taskcluster_urls
-vendored:third_party/python/toml
-vendored:third_party/python/typing_extensions
-vendored:third_party/python/voluptuous
-vendored:third_party/python/yamllint
-vendored:third_party/python/yarl
-vendored:third_party/python/zipp
diff --git a/python/sites/vendor.txt b/python/sites/vendor.txt
index 6b8166a9ef0b..cb5b087afc50 100644
--- a/python/sites/vendor.txt
+++ b/python/sites/vendor.txt
@@ -1,6 +1,4 @@
 pypi:poetry==1.4
 # Pin poetry-core so that the same one is used between Python versions.
 # Otherwise, different versions of poetry-core output different "requirements.txt" contents
-pypi:poetry-core==1.5.1
-vendored:third_party/python/toml
-vendored:third_party/python/voluptuous
+pypi:poetry-core==1.5.1
\ No newline at end of file