pytype: stop excluding mercurial/ui.py ui.extractchoices() is perhaps making assumptions that it shouldn't about the pattern always matching, but presumably we have test coverage for that. PyCharm flags the updated classes with a warning "Class xxx must implement all abstract methods", and suggests adding `abc.ABC` to the superclasses. I'm not sure why, unless it doesn't recognize the `__getattr__()` delegation pattern. Additionally, we can't unconditionally subclass `typing.BinaryIO` because that defeats the `__getattr__` delegation to the wrapped object at runtime. Instead, it has to only subclass during the type checking phase[1]. In any event, this fixes: File "/mnt/c/Users/Matt/hg/mercurial/ui.py", line 1518, in _runpager: Function subprocess.Popen.__new__ was called with the wrong arguments [wrong-arg-types] Expected: (cls, args, bufsize, executable, stdin, stdout: Optional[Union[IO, int]] = ..., ...) Actually passed: (cls, args, bufsize, stdin, stdout: Union[mercurial.utils.procutil.WriteAllWrapper, mercurial.windows.winstdout], ...) File "/mnt/c/Users/Matt/hg/mercurial/ui.py", line 1798, in extractchoices: No attribute 'group' on None [attribute-error] In Optional[Match[bytes]] File "/mnt/c/Users/Matt/hg/mercurial/ui.py", line 1799, in extractchoices: No attribute 'group' on None [attribute-error] In Optional[Match[bytes]] [1] https://stackoverflow.com/q/71365594

# typelib.py - type hint aliases and support
#
# Copyright 2022 Matt Harbison <matt_harbison@yahoo.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

import typing

# Note: this is slightly different from pycompat.TYPE_CHECKING, as using
# pycompat causes the BinaryIO_Proxy type to be resolved to ``object`` when
# used as the base class during a pytype run.
TYPE_CHECKING = typing.TYPE_CHECKING


# The BinaryIO class provides empty methods, which at runtime means that
# ``__getattr__`` on the proxy classes won't get called for the methods that
# should delegate to the internal object.  So to avoid runtime changes because
# of the required typing inheritance, just use BinaryIO when typechecking, and
# ``object`` otherwise.
if TYPE_CHECKING:
    from typing import (
        BinaryIO,
    )

    BinaryIO_Proxy = BinaryIO
else:
    BinaryIO_Proxy = object