Switch to potential new distutils environment variable

cibuildwheel/windows.py

@@ -133,50 +133,10 @@ def setup_setuptools_cross_compile(
     python_configuration: PythonConfiguration,
     python_libs_base: Path,
     env: dict[str, str],
-    cleanup_command_list: list[Callable[[], Any]],
 ) -> None:
-    # We write to distutils_cfg for distutils-based builds to override some
-    # settings. Ideally, we'd pass them on the command line, but since we don't
-    # know that setuptools is going to be used, we can't do it.
-    userprofile = os.getenv("USERPROFILE")
-    if not userprofile:
-        log.warning(
-            "Unable to configure setuptools for cross-compiling because USERPROFILE was not found"
-        )
-        return
-    distutils_cfg = Path(userprofile) / "pydistutils.cfg"
-    if distutils_cfg.is_file():
-        # More than 1000 backup files is likely a different issue, so don't
-        # bother going further than that.
-        for counter in range(1000):
-            distutils_bak = distutils_cfg.with_suffix(f".{counter}.bak")
-            if not distutils_bak.exists():
-                break
-        else:
-            log.warning(
-                f"Unable to configure setuptools for cross-compiling because existing {distutils_cfg} file cannot be backed up: Too many existing backup files were found"
-            )
-            return
-
-        # Move the existing file and restore it when we exit
-        log.notice(
-            f"Preserving {distutils_cfg} as {distutils_bak.name}. It will be restored afterwards."
-        )
-        try:
-            distutils_cfg.replace(distutils_bak)
-        except OSError as exc:
-            log.warning(
-                f"Unable to configure setuptools for cross-compiling because existing {distutils_cfg} file cannot be backed up. Error was {exc}"
-            )
-            return
-        cleanup_command_list.append(lambda: distutils_bak.replace(distutils_cfg))
-    elif distutils_cfg.is_dir():
-        log.warning(
-            f"Unable to configure setuptools for cross-compiling because {distutils_cfg} is a directory"
-        )
-        return
-    else:
-        cleanup_command_list.append(lambda: distutils_cfg.unlink())
+    distutils_cfg = python_libs_base / "extra-setup.cfg"
+    env["DISTUTILS_EXTRA_CONFIG"] = str(distutils_cfg)
+    log.notice(f"Setting DISTUTILS_EXTRA_CONFIG={distutils_cfg} for cross-compilation")
 
     # Ensure our additional import libraries are made available, and explicitly
     # set the platform name
@@ -186,8 +146,6 @@ def setup_setuptools_cross_compile(
     distutils_cfg.write_text(
         textwrap.dedent(
             f"""\
-            # I am a temporary configuration file generated by cibuildwheel.
-            # Please remove me or I will likely break your other builds.
             [build]
             plat_name={plat_name}
             [build_ext]
@@ -221,7 +179,6 @@ def setup_rust_cross_compile(
     python_configuration: PythonConfiguration,
     python_libs_base: Path,
     env: dict[str, str],
-    cleanup_command_list: list[Callable[[], Any]],
 ) -> None:
     # Assume that MSVC will be used, because we already know that we are
     # cross-compiling. MinGW users can set CARGO_BUILD_TARGET themselves
@@ -252,7 +209,6 @@ def setup_python(
     dependency_constraint_flags: Sequence[PathOrStr],
     environment: ParsedEnvironment,
     build_frontend: BuildFrontend,
-    cleanup_command_list: list[Callable[[], Any]],
 ) -> dict[str, str]:
     tmp.mkdir()
     implementation_id = python_configuration.identifier.split("-")[0]
@@ -374,10 +330,8 @@ def setup_python(
 
     if python_libs_base:
         # Set up the environment for various backends to enable cross-compilation
-        setup_setuptools_cross_compile(
-            python_configuration, python_libs_base, env, cleanup_command_list
-        )
-        setup_rust_cross_compile(python_configuration, python_libs_base, env, cleanup_command_list)
+        setup_setuptools_cross_compile(python_configuration, python_libs_base, env)
+        setup_rust_cross_compile(python_configuration, python_libs_base, env)
 
     return env
 
@@ -420,9 +374,6 @@ def build(options: Options, tmp_path: Path) -> None:
                     build_options.dependency_constraints.get_for_python_version(config.version),
                 ]
 
-            # list of callables to do any urgent cleanup, for example,
-            # config files that may bleed into other builds
-            cleanup_command_list: list[Callable[[], Any]] = []
             # install Python
             env = setup_python(
                 identifier_tmp_dir / "build",
@@ -430,10 +381,8 @@ def build(options: Options, tmp_path: Path) -> None:
                 dependency_constraint_flags,
                 build_options.environment,
                 build_options.build_frontend,
-                cleanup_command_list,
             )
 
-            try:
             compatible_wheel = find_compatible_wheel(built_wheels, config.identifier)
             if compatible_wheel:
                 log.step_end()
@@ -529,10 +478,6 @@ def build(options: Options, tmp_path: Path) -> None:
                 if repaired_wheel.name in {wheel.name for wheel in built_wheels}:
                     raise AlreadyBuiltWheelError(repaired_wheel.name)
 
-            finally:
-                while cleanup_command_list:
-                    cleanup_command_list.pop(0)()
-
             if build_options.test_command and options.globals.test_selector(config.identifier):
                 if config.arch == "ARM64" != platform_module.machine():
                     log.warning(