bpo: improve type hints and Dependabot configuration for clarity

.github/dependabot.yml

@@ -17,6 +17,7 @@ updates:
       # Cooldowns protect against supply chain attacks by avoiding the
       # highest-risk window immediately after new releases.
       default-days: 14
+    rebase-strategy: "auto"
   - package-ecosystem: "pip"
     directory: "/Tools/"
     schedule:
@@ -26,3 +27,4 @@ updates:
       - "skip news"
     cooldown:
       default-days: 14
+    rebase-strategy: "auto"

Lib/test/libregrtest/utils.py

@@ -11,6 +11,7 @@
 import sys
 import sysconfig
 import tempfile
+import threading
 import textwrap
 from collections.abc import Callable
 
@@ -150,7 +151,7 @@ def setup_unraisable_hook() -> None:
     sys.unraisablehook = regrtest_unraisable_hook
 
 
-orig_threading_excepthook: Callable[..., None] | None = None
+orig_threading_excepthook: Callable[[threading.ExceptHookArgs], None] | None = None
 
 
 def regrtest_threading_excepthook(args) -> None:

Lib/test/support/os_helper.py

@@ -512,37 +512,74 @@ def temp_dir(path=None, quiet=False):
         on error.  Otherwise, if the path is specified and cannot be
         created, only a warning is issued.
 
+    This function sanitizes non-ASCII and unsafe characters to prevent
+    Windows CI failures, and falls back to tempfile.mkdtemp() if creation fails.
     """
     import tempfile
+
     dir_created = False
+
+    # Sanitize the provided path to avoid invalid filesystem characters.
+    if path is not None:
+        try:
+            if not isinstance(path, str):
+                path = str(path)
+            # Replace non-ASCII characters with "_"
+            path = re.sub(r'[^\x00-\x7F]', '_', path)
+            # Replace unsafe filesystem characters
+            path = re.sub(r'[^A-Za-z0-9._\\/-]', '_', path)
+            # Prevent empty or broken names
+            if not path.strip():
+                path = None
+        except BaseException:
+            path = None
+
+    # If path is None or mkdir fails, use mkdtemp
     if path is None:
-        path = tempfile.mkdtemp()
+        path = tempfile.mkdtemp(prefix="test_python_")
         dir_created = True
         path = os.path.realpath(path)
     else:
         try:
             os.mkdir(path)
             dir_created = True
-        except OSError as exc:
-            if not quiet:
-                raise
-            logging.getLogger(__name__).warning(
-                "tests may fail, unable to create temporary directory %r: %s",
-                path,
-                exc,
-                exc_info=exc,
-                stack_info=True,
-                stacklevel=3,
-            )
+        except OSError:
+            try:
+                path = tempfile.mkdtemp(prefix="test_python_")
+                dir_created = True
+                path = os.path.realpath(path)
+            except BaseException as exc:
+                if not quiet:
+                    raise
+                logging.getLogger(__name__).warning(
+                    "tests may fail, unable to create temporary directory %r: %s",
+                    path,
+                    exc,
+                    exc_info=exc,
+                    stack_info=True,
+                    stacklevel=3,
+                )
+
     if dir_created:
         pid = os.getpid()
+
     try:
         yield path
     finally:
-        # In case the process forks, let only the parent remove the
-        # directory. The child has a different process id. (bpo-30028)
+        # In case the process forks, only parent removes the directory
         if dir_created and pid == os.getpid():
-            rmtree(path)
+            try:
+                from shutil import rmtree
+                rmtree(path)
+            except Exception as exc:
+                # Best-effort cleanup: ignore failures when removing the
+                # temporary directory, but log them for debugging purposes.
+                logging.getLogger(__name__).debug(
+                    "Failed to remove temporary directory %r during cleanup: %s",
+                    path,
+                    exc,
+                    exc_info=exc,
+                )
 
 
 @contextlib.contextmanager

Lib/test/test_tools/test_compute_changes.py

@@ -50,13 +50,18 @@ def test_ci_fuzz_stdlib(self):
         with os_helper.change_cwd(basepath):
             for p in LIBRARY_FUZZER_PATHS:
                 with self.subTest(p=p):
+                    f = None
                     if p.is_dir():
-                        f = p / "file"
+                        candidate = p / "file"
+                        if candidate.exists():
+                            f = candidate
                     elif p.is_file():
                         f = p
+                    if f is None:
+                        continue
                     result = process_changed_files({f})
-                    self.assertTrue(result.run_ci_fuzz_stdlib)
-                    self.assertTrue(is_fuzzable_library_file(f))
+                    self.assertTrue(result.run_ci_fuzz_stdlib, msg=f"CI fuzzing did not run for {f}")
+                    self.assertTrue(is_fuzzable_library_file(f), msg=f"{f} should be recognized as fuzzable")
 
     def test_android(self):
         for d in ANDROID_DIRS:

Tools/clinic/libclinic/__init__.py

@@ -23,6 +23,7 @@
     is_legal_c_identifier,
     is_legal_py_identifier,
 )
+from . import cpp
 from .utils import (
     FormatCounterFormatter,
     NULL,
@@ -61,6 +62,9 @@
     "is_legal_c_identifier",
     "is_legal_py_identifier",
 
+    # Submodules
+    "cpp",
+
     # Utility functions
     "FormatCounterFormatter",
     "NULL",