Open issue: Invalid combination of type qualifiers

[Viicos]

In the introspection module, the inspect_annotation() function can be used to unpack the underlying type expression of an annotation, by stripping and keeping track of the type qualifiers used:

>>> inspect_annotation(
...     ClassVar[int],
...     annotation_source=AnnotationSource.CLASS,
... )
...
InspectedAnnotation(type=int, qualifiers={'class_var'}, metadata=[])

Depending on the annotation source (a class, a function parameter, etc), different type qualifiers are allowed. For classes, users can use Final or ClassVar:

class A:
    a: ClassVar[int]
    b: Final[str]

However, it seems like ClassVar and Final can't be used together. Code sample in pyright playground:

from typing import ClassVar, Final

class A:
    a: Final[ClassVar[int]]  # "ClassVar" is not allowed in this context
    b: ClassVar[Final[int]]  # "Final" is not allowed in this context

There is currently no logic to disallow this. Is it worth checking for this?

As a side note, combining ClassVar and Final is allowed for dataclasses (and types using @dataclass_transform).