Using classes "defined as generic in stubs but not at runtime" as base class triggers inherit-non-class

[mathiasertl]

pylint>=2.9.0 triggers a false positive of inherit-non-class when using a class as base that was defined as a generic in a stub (or mypy plugin) but not at runtime when using the recommended workaround from mypy.

Steps to reproduce

Consider this file:

# pylint: disable=missing-module-docstring,missing-class-docstring
import typing

from django.db import models

if typing.TYPE_CHECKING:
    QuerySetBase = models.QuerySet[models.Model]
else:
    QuerySetBase = models.QuerySet


# class def will trigger: E0239: Inheriting 'QuerySetBase', which is not a class. (inherit-non-class)
class TestQuerySet(QuerySetBase):  
    pass

Current behavior

pylint>=2.9.0 triggers inherit-non-class, version 2.8.3 does not yet trigger that error.

It should be noted that a workaround is to invert the if/else statement like this:

if not typing.TYPE_CHECKING:
    QuerySetBase = models.QuerySet
else:
    QuerySetBase = models.QuerySet[models.Model]

... which will not trigger the error. Still of course, something is clearly happening that is not intended.

Expected behavior

... not trigger that error, obviously ;-)

[Pierre-Sassoulas]

To take into account when doing #3285