File "D:\a\pytest\pytest\.tox\py38-unittestextras\lib\site-packages\pip\_internal\commands\install.py", line 17, in <module>
      from pip._internal.cli.req_command import RequirementCommand, with_cleanup
    File "D:\a\pytest\pytest\.tox\py38-unittestextras\lib\site-packages\pip\_internal\cli\req_command.py", line 16, in <module>
      from pip._internal.index.collector import LinkCollector
    File "D:\a\pytest\pytest\.tox\py38-unittestextras\lib\site-packages\pip\_internal\index\collector.py", line 14, in <module>
      from pip._vendor import html5lib, requests
    File "D:\a\pytest\pytest\.tox\py38-unittestextras\lib\site-packages\pip\_vendor\requests\__init__.py", line 125, in <module>
      from . import utils
    File "D:\a\pytest\pytest\.tox\py38-unittestextras\lib\site-packages\pip\_vendor\requests\utils.py", line 25, in <module>
      from . import certs
    File "D:\a\pytest\pytest\.tox\py38-unittestextras\lib\site-packages\pip\_vendor\requests\certs.py", line 15, in <module>
      from pip._vendor.certifi import where
    File "D:\a\pytest\pytest\.tox\py38-unittestextras\lib\site-packages\pip\_vendor\certifi\__init__.py", line 1, in <module>
      from .core import contents, where
    File "D:\a\pytest\pytest\.tox\py38-unittestextras\lib\site-packages\pip\_vendor\certifi\core.py", line 12, in <module>
      from importlib.resources import path as get_path, read_text
    File "c:\hostedtoolcache\windows\python\3.8.5\x64\lib\importlib\resources.py", line 11, in <module>
      from typing import Iterable, Iterator, Optional, Set, Union   # noqa: F401
    File "D:\a\pytest\pytest\.tox\py38-unittestextras\lib\site-packages\typing.py", line 1359, in <module>
      class Callable(extra=collections_abc.Callable, metaclass=CallableMeta):
    File "D:\a\pytest\pytest\.tox\py38-unittestextras\lib\site-packages\typing.py", line 1007, in __new__
      self._abc_registry = extra._abc_registry
  AttributeError: type object 'Callable' has no attribute '_abc_registry'