Ignore errors in temporary directory cleanup

pip should not exit with an error when it fails to cleanup temporary
files after it has already successfully installed packages.

Author: ales-erjavec

src/pip/_internal/utils/misc.py

@@ -11,6 +11,7 @@
 import sys
 import sysconfig
 import urllib.parse
+from functools import partial
 from io import StringIO
 from itertools import filterfalse, tee, zip_longest
 from types import TracebackType
@@ -123,15 +124,35 @@ def get_prog() -> str:
 # Retry every half second for up to 3 seconds
 # Tenacity raises RetryError by default, explicitly raise the original exception
 @retry(reraise=True, stop=stop_after_delay(3), wait=wait_fixed(0.5))
-def rmtree(dir: str, ignore_errors: bool = False) -> None:
+def rmtree(
+    dir: str,
+    ignore_errors: bool = False,
+    onexc: Optional[Callable[[Any, Any, Any], Any]] = None,
+) -> None:
+    if ignore_errors:
+        onexc = _onerror_ignore
+    elif onexc is None:
+        onexc = _onerror_reraise
     if sys.version_info >= (3, 12):
-        shutil.rmtree(dir, ignore_errors=ignore_errors, onexc=rmtree_errorhandler)
+        shutil.rmtree(dir, onexc=partial(rmtree_errorhandler, onexc=onexc))
     else:
-        shutil.rmtree(dir, ignore_errors=ignore_errors, onerror=rmtree_errorhandler)
+        shutil.rmtree(dir, onerror=partial(rmtree_errorhandler, onexc=onexc))
+
+
+def _onerror_ignore(*_args: Any) -> None:
+    pass
+
+
+def _onerror_reraise(*_args: Any) -> None:
+    raise
 
 
 def rmtree_errorhandler(
-    func: Callable[..., Any], path: str, exc_info: Union[ExcInfo, BaseException]
+    func: Callable[..., Any],
+    path: str,
+    exc_info: Union[ExcInfo, BaseException],
+    *,
+    onexc: Callable[..., Any] = _onerror_reraise,
 ) -> None:
     """On Windows, the files in .svn are read-only, so when rmtree() tries to
     remove them, an exception is thrown.  We catch that here, remove the
@@ -146,10 +167,13 @@ def rmtree_errorhandler(
         # convert to read/write
         os.chmod(path, stat.S_IWRITE)
         # use the original function to repeat the operation
-        func(path)
-        return
-    else:
-        raise
+        try:
+            func(path)
+            return
+        except OSError:
+            pass
+
+    onexc(func, path, exc_info)
 
 
 def display_path(path: str) -> str:

src/pip/_internal/utils/temp_dir.py

@@ -3,8 +3,9 @@
 import logging
 import os.path
 import tempfile
+import traceback
 from contextlib import ExitStack, contextmanager
-from typing import Any, Dict, Generator, Optional, TypeVar, Union
+from typing import Any, Callable, Dict, Generator, Optional, Tuple, Type, TypeVar, Union
 
 from pip._internal.utils.misc import enum, rmtree
 
@@ -106,6 +107,7 @@ def __init__(
         delete: Union[bool, None, _Default] = _default,
         kind: str = "temp",
         globally_managed: bool = False,
+        ignore_cleanup_errors: bool = True,
     ):
         super().__init__()
 
@@ -128,6 +130,7 @@ def __init__(
         self._deleted = False
         self.delete = delete
         self.kind = kind
+        self.ignore_cleanup_errors = ignore_cleanup_errors
 
         if globally_managed:
             assert _tempdir_manager is not None
@@ -170,7 +173,34 @@ def cleanup(self) -> None:
         self._deleted = True
         if not os.path.exists(self._path):
             return
-        rmtree(self._path)
+
+        def onerror(
+            func: Callable[[str], Any],
+            path: str,
+            exc_info: Tuple[Type[BaseException], BaseException, Any],
+        ) -> None:
+            """Log a warning for a `rmtree` error and continue"""
+            exc_val = "\n".join(traceback.format_exception_only(*exc_info[:2]))
+            exc_val = exc_val.rstrip()  # remove trailing new line
+            if func in (os.unlink, os.remove, os.rmdir):
+                logging.warning(
+                    "Failed to remove a temporary file '%s' due to %s.\n"
+                    "You can safely remove it manually.",
+                    path,
+                    exc_val,
+                )
+            else:
+                logging.warning("%s failed with %s.", func.__qualname__, exc_val)
+
+        if self.ignore_cleanup_errors:
+            try:
+                # first try with tenacity; retrying to handle ephemeral errors
+                rmtree(self._path, ignore_errors=False)
+            except OSError:
+                # last pass ignore/log all errors
+                rmtree(self._path, onexc=onerror)
+        else:
+            rmtree(self._path)
 
 
 class AdjacentTempDirectory(TempDirectory):

tests/unit/test_utils.py

@@ -257,9 +257,13 @@ def test_rmtree_errorhandler_reraises_error(tmpdir: Path) -> None:
     except RuntimeError:
         # Make sure the handler reraises an exception
         with pytest.raises(RuntimeError, match="test message"):
-            # Argument 3 to "rmtree_errorhandler" has incompatible type "None"; expected
-            # "Tuple[Type[BaseException], BaseException, TracebackType]"
-            rmtree_errorhandler(mock_func, path, None)  # type: ignore[arg-type]
+            # Argument 3 to "rmtree_errorhandler" has incompatible type
+            # "Union[Tuple[Type[BaseException], BaseException, TracebackType],
+            # Tuple[None, None, None]]"; expected "Tuple[Type[BaseException],
+            # BaseException, TracebackType]"
+            rmtree_errorhandler(
+                mock_func, path, sys.exc_info()  # type: ignore[arg-type]
+            )
 
     mock_func.assert_not_called()
 

tests/unit/test_utils_temp_dir.py

@@ -4,6 +4,7 @@
 import tempfile
 from pathlib import Path
 from typing import Any, Iterator, Optional, Union
+from unittest import mock
 
 import pytest
 
@@ -274,3 +275,25 @@ def test_tempdir_registry_lazy(should_delete: bool) -> None:
             registry.set_delete("test-for-lazy", should_delete)
             assert os.path.exists(path)
         assert os.path.exists(path) == (not should_delete)
+
+
+def test_tempdir_cleanup_ignore_errors() -> None:
+    os_unlink = os.unlink
+
+    # mock os.unlink to fail with EACCES for a specific filename to simulate
+    # how removing a loaded exe/dll behaves.
+    def unlink(name: str, *args: Any, **kwargs: Any) -> None:
+        if "bomb" in name:
+            raise PermissionError(name)
+        else:
+            os_unlink(name)
+
+    with mock.patch("os.unlink", unlink):
+        with TempDirectory(ignore_cleanup_errors=True) as tmp_dir:
+            path = tmp_dir.path
+            with open(os.path.join(path, "bomb"), "a"):
+                pass
+
+    filename = os.path.join(path, "bomb")
+    assert os.path.isfile(filename)
+    os.unlink(filename)