Allow disabling plugins on a one-off

docs/changelog/3468.feature.rst

@@ -0,0 +1 @@
+Allow disabling tox plugins via the ``TOX_DISABLED_EXTERNAL_PLUGINS`` environment variable - by :user:`gaborbernat`.

docs/plugins.rst

@@ -27,6 +27,13 @@ installed. For example:
 
 For more information, refer to :ref:`the user guide <auto-provisioning>`.
 
+Plugins can be disabled via the ``TOX_DISABLED_EXTERNAL_PLUGINS`` environment variable. This variable can be set to a
+comma separated list of plugin names, e.g.:
+
+```bash
+env TOX_DISABLED_EXTERNAL_PLUGINS=tox-uv,tox-extra tox --version
+```
+
 Developing your own plugin
 --------------------------
 

pyproject.toml

@@ -1,7 +1,7 @@
 [build-system]
 build-backend = "hatchling.build"
 requires = [
-  "hatch-vcs>=0.4",
+  "hatch-vcs>=0.5",
   "hatchling>=1.27",
 ]
 
@@ -50,22 +50,17 @@ dynamic = [
   "version",
 ]
 dependencies = [
-  "cachetools>=5.5.1",
+  "cachetools>=6.1",
   "chardet>=5.2",
   "colorama>=0.4.6",
-  "filelock>=3.16.1",
-  "packaging>=24.2",
-  "platformdirs>=4.3.6",
-  "pluggy>=1.5",
-  "pyproject-api>=1.8",
+  "filelock>=3.18",
+  "packaging>=25",
+  "platformdirs>=4.3.8",
+  "pluggy>=1.6",
+  "pyproject-api>=1.9.1",
   "tomli>=2.2.1; python_version<'3.11'",
-  "typing-extensions>=4.12.2; python_version<'3.11'",
-  "virtualenv>=20.31",
-]
-optional-dependencies.test = [
-  "devpi-process>=1.0.2",
-  "pytest>=8.3.4",
-  "pytest-mock>=3.14",
+  "typing-extensions>=4.14; python_version<'3.11'",
+  "virtualenv>=20.31.2",
 ]
 urls.Documentation = "https://tox.wiki"
 urls.Homepage = "http://tox.readthedocs.org"
@@ -83,35 +78,35 @@ dev = [
 test = [
   "build[virtualenv]>=1.2.2.post1",
   "covdefaults>=2.3",
-  "coverage>=7.9.1",
+  "coverage>=7.9.2",
   "detect-test-pollution>=1.2",
   "devpi-process>=1.0.2",
-  "diff-cover>=9.2",
+  "diff-cover>=9.4.1",
   "distlib>=0.3.9",
   "flaky>=3.8.1",
-  "hatch-vcs>=0.4",
+  "hatch-vcs>=0.5",
   "hatchling>=1.27",
-  "psutil>=6.1.1",
-  "pytest>=8.3.4",
-  "pytest-cov>=5",
-  "pytest-mock>=3.14",
-  "pytest-xdist>=3.6.1",
+  "psutil>=7",
+  "pytest>=8.4.1",
+  "pytest-cov>=6.2.1",
+  "pytest-mock>=3.14.1",
+  "pytest-xdist>=3.8",
   "re-assert>=1.1",
-  "setuptools>=75.8",
-  "time-machine>=2.15; implementation_name!='pypy'",
+  "setuptools>=80.9",
+  "time-machine>=2.16; implementation_name!='pypy'",
   "wheel>=0.45.1",
 ]
 type = [
-  "mypy==1.15",
-  "types-cachetools>=5.5.0.20240820",
+  "mypy==1.16.1",
+  "types-cachetools>=6.0.0.20250525",
   "types-chardet>=5.0.4.6",
   { include-group = "test" },
 ]
 docs = [
   "furo>=2024.8.6",
-  "sphinx>=8.1.3",
+  "sphinx>=8.2.3",
   "sphinx-argparse-cli>=1.19",
-  "sphinx-autodoc-typehints>=3.0.1",
+  "sphinx-autodoc-typehints>=3.2",
   "sphinx-copybutton>=0.5.2",
   "sphinx-inline-tabs>=2023.4.21",
   "sphinxcontrib-towncrier>=0.2.1a0",
@@ -121,13 +116,13 @@ fix = [
   "pre-commit-uv>=4.1.4",
 ]
 pkg-meta = [
-  "check-wheel-contents>=0.6.1",
+  "check-wheel-contents>=0.6.2",
   "twine>=6.1",
-  "uv>=0.5.29",
+  "uv>=0.7.19",
 ]
 release = [
   "gitpython>=3.1.44",
-  "packaging>=24.2",
+  "packaging>=25",
   "towncrier>=24.8",
 ]
 

src/tox/config/cli/parser.py

@@ -263,7 +263,7 @@ def add_argument_group(self, *args: Any, **kwargs: Any) -> Any:
 
             def add_mutually_exclusive_group(**e_kwargs: Any) -> Any:
                 def add_argument(*a_args: str, of_type: type[Any] | None = None, **a_kwargs: Any) -> Action:
-                    res_args: Action = prev_add_arg(*a_args, **a_kwargs)  # type: ignore[has-type]
+                    res_args: Action = prev_add_arg(*a_args, **a_kwargs)
                     arguments.append((a_args, of_type, a_kwargs))
                     return res_args
 

src/tox/plugin/manager.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import os
 from typing import TYPE_CHECKING, Any
 
 import pluggy
@@ -49,7 +50,7 @@ def _register_plugins(self, inline: ModuleType | None) -> None:
 
         if inline is not None:
             self.manager.register(inline)
-        self.manager.load_setuptools_entrypoints(NAME)
+        self._load_external_plugins()
         internal_plugins = (
             loader_api,
             provision,
@@ -74,6 +75,11 @@ def _register_plugins(self, inline: ModuleType | None) -> None:
         self.manager.register(state)
         self.manager.check_pending()
 
+    def _load_external_plugins(self) -> None:
+        for name in os.environ.get("TOX_DISABLED_EXTERNAL_PLUGINS", "").split(","):
+            self.manager.set_blocked(name)
+        self.manager.load_setuptools_entrypoints(NAME)
+
     def tox_add_option(self, parser: ToxParser) -> None:
         self.manager.hook.tox_add_option(parser=parser)
 

src/tox/pytest.py

@@ -82,7 +82,10 @@ def _load_inline(path: Path) -> ModuleType | None:  # register only on first run
 @contextmanager
 def check_os_environ() -> Iterator[None]:
     old = os.environ.copy()
-    to_clean = {k: os.environ.pop(k, None) for k in (ENV_VAR_KEY, "TOX_WORK_DIR", "PYTHONPATH", "COV_CORE_CONTEXT")}
+    to_clean = {
+        k: os.environ.pop(k, None)
+        for k in (ENV_VAR_KEY, "TOX_WORK_DIR", "PYTHONPATH", "COV_CORE_CONTEXT", "TOX_DISABLED_EXTERNAL_PLUGINS")
+    }
 
     yield
 
@@ -93,6 +96,7 @@ def check_os_environ() -> Iterator[None]:
     new = os.environ
     extra = {k: new[k] for k in set(new) - set(old)}
     extra.pop("PLAT", None)
+    extra.pop("TOX_DISABLED_EXTERNAL_PLUGINS", None)
     miss = {k: old[k] for k in set(old) - set(new)}
     diff = {
         f"{k} = {old[k]} vs {new[k]}" for k in set(old) & set(new) if old[k] != new[k] and not k.startswith("PYTEST_")

tests/plugin/test_plugin.py

@@ -13,6 +13,7 @@
 from tox.config.sets import ConfigSet, CoreConfigSet, EnvConfigSet
 from tox.execute import Outcome
 from tox.plugin import impl
+from tox.plugin.manager import Plugin
 from tox.pytest import ToxProjectCreator, register_inline_plugin
 from tox.session.state import State
 from tox.tox_env.api import ToxEnv
@@ -21,6 +22,7 @@
 if TYPE_CHECKING:
     from pathlib import Path
 
+    from pluggy import PluginManager
     from pytest_mock import MockerFixture
 
 
@@ -268,3 +270,45 @@ def tox_after_run_commands(tox_env: ToxEnv, exit_code: int, outcomes: list[Outco
     project = tox_project({"tox.ini": "[testenv]\npackage=skip"})
     result = project.run("r")
     result.assert_success()
+
+
+@pytest.mark.parametrize(
+    ("env_val", "expect_a", "expect_b"),
+    [
+        pytest.param("", True, True, id="none_disabled"),
+        pytest.param("dummy_plugin_a,dummy_plugin_b", False, False, id="both_disabled"),
+        pytest.param("dummy_plugin_a", False, True, id="only_a_disabled"),
+        pytest.param("dummy_plugin_b", True, False, id="only_b_disabled"),
+    ],
+)
+def test_disable_external_plugins(
+    tox_project: ToxProjectCreator,
+    mocker: MockerFixture,
+    env_val: str,
+    expect_a: bool,
+    expect_b: bool,
+) -> None:
+    class DummyPluginA:
+        @staticmethod
+        @impl
+        def tox_add_option(parser: ToxParser) -> None:  # noqa: ARG004
+            logging.warning("dummy plugin A called")
+
+    class DummyPluginB:
+        @staticmethod
+        @impl
+        def tox_add_option(parser: ToxParser) -> None:  # noqa: ARG004
+            logging.warning("dummy plugin B called")
+
+    def fake_load_entrypoints(self: PluginManager, name: str) -> None:  # noqa: ARG001
+        self.register(DummyPluginA(), name="dummy_plugin_a")
+        self.register(DummyPluginB(), name="dummy_plugin_b")
+
+    mocker.patch("pluggy.PluginManager.load_setuptools_entrypoints", fake_load_entrypoints)
+    mocker.patch.dict(os.environ, {"TOX_DISABLED_EXTERNAL_PLUGINS": env_val})
+    mocker.patch("tox.plugin.manager.MANAGER", Plugin())
+    project = tox_project({"tox.ini": ""})
+    result = project.run("--version")
+    result.assert_success()
+    assert ("dummy plugin A called" in result.out) == expect_a
+    assert ("dummy plugin B called" in result.out) == expect_b

tests/session/cmd/test_sequential.py

@@ -71,7 +71,7 @@ def test_result_json_sequential(
             "setup.py": "from setuptools import setup\nsetup(name='a', version='1.0', py_modules=['run'],"
             "install_requires=['setuptools>44'])",
             "run.py": "print('run')",
-            "pyproject.toml": '[build-system]\nrequires=["setuptools","wheel"]\nbuild-backend="setuptools.build_meta"',
+            "pyproject.toml": '[build-system]\nrequires=["setuptools"]\nbuild-backend="setuptools.build_meta"',
         },
     )
     log = project.path / "log.json"
@@ -104,7 +104,7 @@ def test_result_json_sequential(
     packaging_test = get_cmd_exit_run_id(log_report, ".pkg", "test")
     assert packaging_test == [(None, "build_wheel")]
     packaging_installed = log_report["testenvs"][".pkg"].pop("installed_packages")
-    assert {i[: i.find("==")] for i in packaging_installed} == {"pip", "setuptools", "wheel"}
+    assert {i[: i.find("==")] for i in packaging_installed} == {"pip", "setuptools"}
 
     result_py = log_report["testenvs"]["py"].pop("result")
     assert result_py.pop("duration") > 0

tests/test_provision.py

@@ -91,10 +91,13 @@ def tox_wheels(tox_wheel: Path, tmp_path_factory: TempPathFactory) -> list[Path]
         assert distribution.requires is not None
         for req in distribution.requires:
             requirement = Requirement(req)
-            if not requirement.extras:  # pragma: no branch  # we don't need to install any extras (tests/docs/etc)
+            if not requirement.extras:  # pragma: no branch # we don't need to install any extras (tests/docs/etc)
                 cmd.append(req)
         check_call(cmd)
         result.extend(wheel_cache.iterdir())
+        res = "\n".join(str(i) for i in result)
+        with elapsed(f"acquired dependencies for current tox: {res}"):
+            pass
         return result
 
 

tests/tox_env/python/virtual_env/package/conftest.py

@@ -20,8 +20,8 @@ def pkg_with_extras_project(tmp_path_factory: pytest.TempPathFactory) -> Path:
     [options]
     packages = find:
     install_requires =
-        platformdirs>=2.1
-        colorama>=0.4.3
+        platformdirs>=4.3.8
+        colorama>=0.4.6
 
     [options.extras_require]
     testing =

tests/tox_env/python/virtual_env/package/test_package_cmd_builder.py

@@ -27,7 +27,7 @@ def test_tox_install_pkg_wheel(tox_project: ToxProjectCreator, pkg_with_extras_p
     result = proj.run("r", "-e", "py", "--installpkg", str(pkg_with_extras_project_wheel))
     result.assert_success()
     calls = [(i[0][0].conf.name, i[0][3].run_id, i[0][3].cmd[5:]) for i in execute_calls.call_args_list]
-    deps = ["black>=3", "colorama>=0.4.3", "flake8", "platformdirs>=2.1", "sphinx-rtd-theme<1,>=0.4.3", "sphinx>=3"]
+    deps = ["black>=3", "colorama>=0.4.6", "flake8", "platformdirs>=4.3.8", "sphinx-rtd-theme<1,>=0.4.3", "sphinx>=3"]
     expected = [
         ("py", "install_package_deps", deps),
         ("py", "install_package", ["--force-reinstall", "--no-deps", str(pkg_with_extras_project_wheel)]),
@@ -61,7 +61,7 @@ def test_tox_install_pkg_sdist(tox_project: ToxProjectCreator, pkg_with_extras_p
     result = proj.run("r", "-e", "py", "--installpkg", str(pkg_with_extras_project_sdist))
     result.assert_success()
     calls = [(i[0][0].conf.name, i[0][3].run_id, i[0][3].cmd[5:]) for i in execute_calls.call_args_list]
-    deps = ["black>=3", "colorama>=0.4.3", "flake8", "platformdirs>=2.1", "sphinx-rtd-theme<1,>=0.4.3", "sphinx>=3"]
+    deps = ["black>=3", "colorama>=0.4.6", "flake8", "platformdirs>=4.3.8", "sphinx-rtd-theme<1,>=0.4.3", "sphinx>=3"]
     assert calls == [
         (".pkg_external_sdist_meta", "install_requires", ["setuptools", "wheel"]),
         (".pkg_external_sdist_meta", "_optional_hooks", []),

tests/tox_env/python/virtual_env/package/test_package_pyproject.py

@@ -51,8 +51,15 @@ def test_get_package_deps_different_extras(pkg_with_extras_project: Path, tox_pr
         if i[0][3].run_id.startswith("install_package_deps")
     }
     assert installs == {
-        "a": ["colorama>=0.4.3", "platformdirs>=2.1", "setuptools", "sphinx-rtd-theme<1,>=0.4.3", "sphinx>=3", "wheel"],
-        "b": ["black>=3", "colorama>=0.4.3", "flake8", "platformdirs>=2.1"],
+        "a": [
+            "colorama>=0.4.6",
+            "platformdirs>=4.3.8",
+            "setuptools",
+            "sphinx-rtd-theme<1,>=0.4.3",
+            "sphinx>=3",
+            "wheel",
+        ],
+        "b": ["black>=3", "colorama>=0.4.6", "flake8", "platformdirs>=4.3.8"],
     }
 
 

tests/tox_env/python/virtual_env/package/test_python_package_util.py

@@ -29,7 +29,7 @@ def test_load_dependency_no_extra(pkg_with_extras: PathDistribution) -> None:
     requires = pkg_with_extras.requires
     assert requires is not None
     result = dependencies_with_extras([Requirement(i) for i in requires], set(), "")
-    for left, right in zip_longest(result, (Requirement("platformdirs>=2.1"), Requirement("colorama>=0.4.3"))):
+    for left, right in zip_longest(result, (Requirement("platformdirs>=4.3.8"), Requirement("colorama>=0.4.6"))):
         assert isinstance(right, Requirement)
         assert str(left) == str(right)
 
@@ -41,8 +41,8 @@ def test_load_dependency_many_extra(pkg_with_extras: PathDistribution) -> None:
     result = dependencies_with_extras([Requirement(i) for i in requires], {"docs", "testing"}, "")
     sphinx = [Requirement("sphinx>=3"), Requirement("sphinx-rtd-theme<1,>=0.4.3")]
     exp = [
-        Requirement("platformdirs>=2.1"),
-        Requirement("colorama>=0.4.3"),
+        Requirement("platformdirs>=4.3.8"),
+        Requirement("colorama>=0.4.6"),
         *(sphinx if sys.version_info[0:2] <= (3, 8) else []),
         Requirement(f'covdefaults>=1.2; python_version == "2.7" or python_version == "{py_ver}"'),
         Requirement(f'pytest>=5.4.1; python_version == "{py_ver}"'),

tox.toml

@@ -1,4 +1,4 @@
-requires = ["tox>=4.24.1"]
+requires = ["tox>=4.27"]
 env_list = ["fix", "3.14t", "3.14", "3.13", "3.12", "3.11", "3.10", "3.9", "cov", "type", "docs", "pkg_meta"]
 skip_missing_interpreters = true