Error typechecking ManyToManyField manager `request.user.groups.all()`

[willbeaufoy]

Bug report

What's wrong

If I use request.user.groups.all() in a view (request being an instance of django.http.HttpRequest), this runs fine but mypy complains with

error: Item "ManyToManyField[Sequence[Group], RelatedManager[Group]]" of "Union[ManyToManyField[Sequence[Group], RelatedManager[Group]], EmptyManager]" has no attribute "all"

How is that should be

Typechecking should pass without errors.

System information

• OS: Ubuntu 20.04
• python version: 3.9.10
• django version: 4.0.2
• mypy version: 0.910
• django-stubs version: 1.9.0
• django-stubs-ext version: 0.3.1