AMD64 Windows8.1 Refleaks 3.9:
https://buildbot.python.org/all/#/builders/6/builds/31

2:16:22 load avg: 7.33 [364/425/2] test_asyncio crashed (Exit code 1) -- running: test_decimal (2 min 33 sec), test_dbm (2 min 53 sec), test_bufio (18 min 18 sec)
["test_asyncio", 0, 268.7466852, null]
beginning 6 repetitions
123456
D:\buildarea\3.9.ware-win81-release.refleak\build\lib\subprocess.py:1052: ResourceWarning: subprocess 2724 is still running
  _warn("subprocess %s is still running" % self.pid,
ResourceWarning: Enable tracemalloc to get the object allocation traceback
D:\buildarea\3.9.ware-win81-release.refleak\build\lib\asyncio\windows_utils.py:112: ResourceWarning: unclosed <PipeHandle handle=2008>
  _warn(f"unclosed {self!r}", ResourceWarning, source=self)
ResourceWarning: Enable tracemalloc to get the object allocation traceback
D:\buildarea\3.9.ware-win81-release.refleak\build\lib\asyncio\windows_utils.py:112: ResourceWarning: unclosed <PipeHandle handle=1364>
  _warn(f"unclosed {self!r}", ResourceWarning, source=self)
ResourceWarning: Enable tracemalloc to get the object allocation traceback
D:\buildarea\3.9.ware-win81-release.refleak\build\lib\asyncio\windows_utils.py:112: ResourceWarning: unclosed <PipeHandle handle=1968>
  _warn(f"unclosed {self!r}", ResourceWarning, source=self)
ResourceWarning: Enable tracemalloc to get the object allocation traceback
test test_asyncio failed -- Traceback (most recent call last):
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\test\test_asyncio\test_windows_utils.py", line 111, in test_popen
    self.assertEqual(res, _winapi.WAIT_OBJECT_0)
AssertionError: 258 != 0

Traceback (most recent call last):
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\test\support\__init__.py", line 906, in temp_dir
    yield path
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\test\support\__init__.py", line 958, in temp_cwd
    yield cwd_dir
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\test\libregrtest\main.py", line 638, in main
    self._main(tests, kwargs)
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\test\libregrtest\main.py", line 658, in _main
    run_tests_worker(self.ns, self.worker_test_name)
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\test\libregrtest\runtest_mp.py", line 86, in run_tests_worker
    sys.exit(0)
SystemExit: 0

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\test\support\__init__.py", line 329, in _force_run
    return func(*args)
PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: 'D:\\buildarea\\3.9.ware-win81-release.refleak\\build\\build\\test_python_6648�\\test_python_worker_1760�'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\runpy.py", line 197, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\test\regrtest.py", line 47, in <module>
    _main()
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\test\regrtest.py", line 43, in _main
    main()
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\test\libregrtest\main.py", line 716, in main
    Regrtest().main(tests=tests, **kwargs)
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\test\libregrtest\main.py", line 638, in main
    self._main(tests, kwargs)
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\contextlib.py", line 135, in __exit__
    self.gen.throw(type, value, traceback)
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\test\support\__init__.py", line 958, in temp_cwd
    yield cwd_dir
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\contextlib.py", line 135, in __exit__
    self.gen.throw(type, value, traceback)
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\test\support\__init__.py", line 911, in temp_dir
    rmtree(path)
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\test\support\__init__.py", line 452, in rmtree
    _rmtree(path)
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\test\support\__init__.py", line 393, in _rmtree
    _waitfor(lambda p: _force_run(p, os.rmdir, p), path)
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\test\support\__init__.py", line 340, in _waitfor
    func(pathname)
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\test\support\__init__.py", line 393, in <lambda>
    _waitfor(lambda p: _force_run(p, os.rmdir, p), path)
  File "D:\buildarea\3.9.ware-win81-release.refleak\build\lib\test\support\__init__.py", line 335, in _force_run
    return func(*args)
PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: 'D:\\buildarea\\3.9.ware-win81-release.refleak\\build\\build\\test_python_6648�\\test_python_worker_1760�'

New changeset be1cb3214d09d4bf0288bc45f3c1f167f67e4514 by Victor Stinner in branch 'main':
bpo-44287: asyncio test_popen() uses longer timeout (GH-26832)
https://github.com/python/cpython/commit/be1cb3214d09d4bf0288bc45f3c1f167f67e4514

New changeset c032a12cbb7d6e2d6a292b0e9220c33ef7349d28 by Miss Islington (bot) in branch '3.10':
bpo-44287: asyncio test_popen() uses longer timeout (GH-26832)
https://github.com/python/cpython/commit/c032a12cbb7d6e2d6a292b0e9220c33ef7349d28

New changeset 0ff487b8abe70f091285acf367b795861eed8049 by Miss Islington (bot) in branch '3.9':
bpo-44287: asyncio test_popen() uses longer timeout (GH-26832)
https://github.com/python/cpython/commit/0ff487b8abe70f091285acf367b795861eed8049