fix: workaround for Windows Python 3.7 TemporaryDirectory bug

src/scikit_build_core/_shutil.py

@@ -1,9 +1,12 @@
 from __future__ import annotations
 
+import contextlib
 import dataclasses
 import os
+import stat
 import subprocess
-from collections.abc import Iterable
+import sys
+from collections.abc import Generator, Iterable
 from typing import ClassVar
 
 from ._logging import logger
@@ -78,3 +81,26 @@ def _key_diff(self, k: str) -> str:
         if k in self._prev_env and k not in self.env:
             return "-"
         return " "
+
+
+def _fix_all_permissions(directory: str) -> None:
+    """
+    Makes sure the write permission is set. Only run this on Windows.
+    """
+    with os.scandir(directory) as it:
+        for entry in it:
+            if entry.is_dir():
+                _fix_all_permissions(entry.path)
+                continue
+            mode = stat.S_IMODE(entry.stat().st_mode)
+            if not mode & stat.S_IWRITE:
+                os.chmod(entry.path, mode | stat.S_IWRITE)  # noqa: PTH101
+
+
+@contextlib.contextmanager
+def fix_win_37_all_permissions(tmpdir: str) -> Generator[None, None, None]:
+    try:
+        yield
+    finally:
+        if sys.version_info < (3, 8) and sys.platform.startswith("win"):
+            _fix_all_permissions(tmpdir)

src/scikit_build_core/build/wheel.py

@@ -14,6 +14,7 @@
 from .. import __version__
 from .._compat import tomllib
 from .._logging import logger, rich_print
+from .._shutil import fix_win_37_all_permissions
 from ..builder.builder import Builder, archs_to_tags, get_archs
 from ..builder.wheel_tag import WheelTag
 from ..cmake import CMake, CMaker
@@ -102,7 +103,7 @@ def _build_wheel_impl(
         f"[red]({action})[/red]",
     )
 
-    with tempfile.TemporaryDirectory() as tmpdir:
+    with tempfile.TemporaryDirectory() as tmpdir, fix_win_37_all_permissions(tmpdir):
         build_tmp_folder = Path(tmpdir)
         wheel_dir = build_tmp_folder / "wheel"
 

tests/test_shutil.py

@@ -0,0 +1,53 @@
+from __future__ import annotations
+
+import shutil
+import stat
+import sys
+import tempfile
+from pathlib import Path
+
+import pytest
+
+from scikit_build_core._shutil import _fix_all_permissions, fix_win_37_all_permissions
+
+
+def _make_dir_with_ro(tmp_path: Path) -> Path:
+    base = tmp_path / "fix_all_perm"
+    base.mkdir()
+    base.joinpath("normal_file.txt").touch()
+    ro = base / "read_only.txt"
+    ro.touch()
+    ro.chmod(stat.S_IREAD)
+    nested = base / "nested"
+    nested.mkdir()
+    ro2 = nested / "read_only_2.txt"
+    ro2.touch()
+    ro2.chmod(stat.S_IREAD)
+
+    # Validity check
+    assert not stat.S_IMODE(ro2.stat().st_mode) & stat.S_IWRITE
+
+    return base
+
+
+@pytest.fixture()
+def make_dir_with_ro(tmp_path: Path) -> Path:
+    return _make_dir_with_ro(tmp_path)
+
+
+def test_broken_all_permissions(make_dir_with_ro: Path) -> None:
+    if sys.platform.startswith("win"):
+        with pytest.raises(PermissionError):
+            shutil.rmtree(make_dir_with_ro)
+    else:
+        shutil.rmtree(make_dir_with_ro)
+
+
+def test_fix_all_permissions(make_dir_with_ro: Path) -> None:
+    _fix_all_permissions(str(make_dir_with_ro))
+    shutil.rmtree(make_dir_with_ro)
+
+
+def test_tmpdir():
+    with tempfile.TemporaryDirectory() as tmp, fix_win_37_all_permissions(tmp):
+        _make_dir_with_ro(Path(tmp))