test: add test for _make_cachedir BaseException cleanup

Co-authored-by: Cursor AI <ai@cursor.sh>
Co-authored-by: Anthropic Claude Opus 4.5 <claude@anthropic.com>

Author: 3 people

testing/test_cacheprovider.py

@@ -1360,3 +1360,36 @@ def test_cachedir_tag(pytester: Pytester) -> None:
 def test_clioption_with_cacheshow_and_help(pytester: Pytester) -> None:
     result = pytester.runpytest("--cache-show", "--help")
     assert result.ret == 0
+
+
+def test_make_cachedir_cleans_up_on_base_exception(
+    tmp_path: Path,
+    monkeypatch: MonkeyPatch,
+) -> None:
+    """Ensure _make_cachedir cleans up the temp directory on BaseException.
+
+    When a BaseException (like KeyboardInterrupt) is raised during cache
+    directory creation, the temporary directory should be cleaned up before
+    re-raising the exception.
+    """
+    from _pytest.cacheprovider import _make_cachedir
+
+    target = tmp_path / ".pytest_cache"
+
+    def raise_keyboard_interrupt(self: Path, target: Path) -> None:
+        raise KeyboardInterrupt("simulated interrupt")
+
+    # Patch Path.rename only for the duration of the _make_cachedir call
+    with monkeypatch.context() as m:
+        m.setattr(Path, "rename", raise_keyboard_interrupt)
+
+        # Verify the exception is re-raised
+        with pytest.raises(KeyboardInterrupt, match="simulated interrupt"):
+            _make_cachedir(target)
+
+    # Verify no temp directories were left behind
+    temp_dirs = list(tmp_path.glob("pytest-cache-files-*"))
+    assert temp_dirs == [], f"Temp directories not cleaned up: {temp_dirs}"
+
+    # Verify the target directory was not created
+    assert not target.exists()