Generate distutils-stubs on install

Author: Avasam

mypy.ini

@@ -5,7 +5,7 @@
 strict = False
 
 # Early opt-in even when strict = False
-# warn_unused_ignores = True # Disabled until we have distutils stubs for Python 3.12+
+# warn_unused_ignores = True # Disabled as long as there's inconsistent typing issues between pypa and stdlib's distutils
 warn_redundant_casts = True
 enable_error_code = ignore-without-code
 
@@ -48,14 +48,6 @@ disable_error_code =
 [mypy-pkg_resources.tests.*]
 disable_error_code = import-not-found
 
-# - distutils doesn't exist on Python 3.12, unfortunately, this means typing
-#   will be missing for subclasses of distutils on Python 3.12 until either:
-#     - support for `SETUPTOOLS_USE_DISTUTILS=stdlib` is dropped (#3625)
-#       for setuptools to import `_distutils` directly
-#     - or non-stdlib distutils typings are exposed
-[mypy-distutils.*]
-ignore_missing_imports = True
-
 #  - wheel: does not intend on exposing a programmatic API https://github.com/pypa/wheel/pull/610#issuecomment-2081687671
 [mypy-wheel.*]
 follow_untyped_imports = True

newsfragments/4861.feature.rst

@@ -0,0 +1 @@
+``setuptools`` now provide its own ``distutils-stubs`` instead of relying on typeshed -- by :user:`Avasam`

pyrightconfig.json

@@ -12,6 +12,8 @@
 	],
 	// Our testing setup doesn't allow passing CLI arguments, so local devs have to set this manually.
 	// "pythonVersion": "3.9",
+	// Allow using distutils-stubs on Python 3.12+
+	"reportMissingModuleSource": false,
 	// For now we don't mind if mypy's `type: ignore` comments accidentally suppresses pyright issues
 	"enableTypeIgnoreComments": true,
 	"typeCheckingMode": "basic",

setup.py

@@ -3,6 +3,7 @@
 import os
 import sys
 import textwrap
+from pathlib import Path
 
 import setuptools
 from setuptools.command.install import install
@@ -37,6 +38,22 @@ def pypi_link(pkg_filename):
     return '/'.join(parts)
 
 
+vendored_distutils_path = Path(here) / "setuptools" / "_distutils"
+
+
+def generate_distutils_stubs(destination: Path) -> None:
+    for path in vendored_distutils_path.rglob("*.py"):
+        relative_path = path.relative_to(vendored_distutils_path)
+        if relative_path.parts[0] == "tests":
+            continue
+        stub_path = (destination / relative_path).with_suffix(".pyi")
+        stub_path.parent.mkdir(parents=True, exist_ok=True)
+        module = "setuptools._distutils." + str(relative_path.with_suffix("")).replace(
+            os.sep, "."
+        ).removesuffix(".__init__")
+        stub_path.write_text(f"from {module} import *\n")
+
+
 class install_with_pth(install):
     """
     Custom install command to install a .pth file for distutils patching.
@@ -68,6 +85,10 @@ def initialize_options(self):
         install.initialize_options(self)
         self.extra_path = self._pth_name, self._pth_contents
 
+    def run(self):
+        install.run(self)
+        generate_distutils_stubs(Path(self.install_lib) / 'distutils-stubs')
+
     def finalize_options(self):
         install.finalize_options(self)
         self._restore_install_lib()

setuptools/__init__.py

@@ -1,9 +1,4 @@
 """Extensions to the 'distutils' for large or complex distributions"""
-# mypy: disable_error_code=override
-# Command.reinitialize_command has an extra **kw param that distutils doesn't have
-# Can't disable on the exact line because distutils doesn't exists on Python 3.12
-# and mypy isn't aware of distutils_hack, causing distutils.core.Command to be Any,
-# and a [unused-ignore] to be raised on 3.12+
 
 from __future__ import annotations
 
@@ -211,7 +206,7 @@ def ensure_string_list(self, option: str) -> None:
                     f"'{option}' must be a list of strings (got {val!r})"
                 )
 
-    @overload
+    @overload  # type: ignore[override] # extra **kw param that distutils doesn't have
     def reinitialize_command(
         self, command: str, reinit_subcommands: bool = False, **kw
     ) -> _Command: ...
@@ -224,7 +219,7 @@ def reinitialize_command(
     ) -> _Command:
         cmd = _Command.reinitialize_command(self, command, reinit_subcommands)
         vars(cmd).update(kw)
-        return cmd  # pyright: ignore[reportReturnType] # pypa/distutils#307
+        return cmd
 
     @abstractmethod
     def initialize_options(self) -> None:

setuptools/build_meta.py

@@ -91,11 +91,11 @@ def patch(cls):
         for the duration of this context.
         """
         orig = distutils.core.Distribution
-        distutils.core.Distribution = cls  # type: ignore[misc] # monkeypatching
+        distutils.core.Distribution = cls
         try:
             yield
         finally:
-            distutils.core.Distribution = orig  # type: ignore[misc] # monkeypatching
+            distutils.core.Distribution = orig
 
 
 @contextlib.contextmanager

setuptools/command/build_ext.py

@@ -248,7 +248,7 @@ def setup_shlib_compiler(self):
             compiler.set_link_objects(self.link_objects)
 
         # hack so distutils' build_extension() builds a library instead
-        compiler.link_shared_object = link_shared_object.__get__(compiler)  # type: ignore[method-assign]
+        compiler.link_shared_object = link_shared_object.__get__(compiler)
 
     def get_export_symbols(self, ext):
         if isinstance(ext, Library):

setuptools/command/sdist.py

@@ -50,7 +50,7 @@ class sdist(orig.sdist):
     ]
 
     distribution: Distribution  # override distutils.dist.Distribution with setuptools.dist.Distribution
-    negative_opt: ClassVar[dict[str, str]] = {}
+    negative_opt: ClassVar[dict[str, str]] = {}  # type: ignore[misc] # TODO: Fix upstream
 
     README_EXTENSIONS = ['', '.rst', '.txt', '.md']
     READMES = tuple(f'README{ext}' for ext in README_EXTENSIONS)

setuptools/command/setopt.py

@@ -37,7 +37,7 @@ def edit_config(filename, settings, dry_run=False):
     """
     log.debug("Reading configuration from %s", filename)
     opts = configparser.RawConfigParser()
-    opts.optionxform = lambda optionstr: optionstr  # type: ignore[method-assign] # overriding method
+    opts.optionxform = lambda optionstr: optionstr
     _cfg_read_utf8_with_fallback(opts, filename)
 
     for section, options in settings.items():

setuptools/config/setupcfg.py

@@ -17,7 +17,7 @@
 from collections import defaultdict
 from collections.abc import Iterable, Iterator
 from functools import partial, wraps
-from typing import TYPE_CHECKING, Any, Callable, ClassVar, Generic, TypeVar, cast
+from typing import TYPE_CHECKING, Any, Callable, ClassVar, Generic, TypeVar
 
 from packaging.markers import default_environment as marker_env
 from packaging.requirements import InvalidRequirement, Requirement
@@ -101,8 +101,7 @@ def _apply(
     filenames = [*other_files, filepath]
 
     try:
-        # TODO: Temporary cast until mypy 1.12 is released with upstream fixes from typeshed
-        _Distribution.parse_config_files(dist, filenames=cast(list[str], filenames))
+        _Distribution.parse_config_files(dist, filenames=filenames)  # type: ignore[arg-type] # Vendored version of distutils supports PathLike
         handlers = parse_configuration(
             dist, dist.command_options, ignore_option_errors=ignore_option_errors
         )