False positive E1136: unsubscriptable-object when generic class defines __class_getitem__

[couteau]

Bug description

possibly related to #3488

when a generic class includes a definition of __class_getitem__, instances created from an annotated class are flagged as "unsubscriptable-object" even when the class itself also includes a __getitem__ method.

Example test.py file:

"""__class_getitem__ test"""
from typing import TypeVar, Generic

T = TypeVar("T")

class Test(Generic[T]):
    """Test class"""
    def __class_getitem__(cls, *args):
        return super().__class_getitem__(*args)

    def __init__(self, iterable):
        super().__init__()
        self._list: list[T] = list(iterable)

    def __getitem__(self, index):
        return self._list[index]

t = Test[int]([1, 2, 3])

print(t[1])

Command used

pylint -E test.py

Pylint output

************* Module test
test.py:21:6: E1136: Value 't' is unsubscriptable (unsubscriptable-object)

Expected behavior

the instance t is subscriptable, so no error should be reported

Pylint version

pylint 3.3.4
astroid 3.3.8
Python 3.9.21 | packaged by conda-forge | (main, Dec  5 2024, 13:47:18)
[Clang 18.1.8 ]

OS / Environment

MacOS, ARM (M1), running Sequoia