False negative with accessing super types private member from sub type

[KotlinIsland]

Following code shows no errors from mypy but will fail at runtime.

class A:
    def __a(self) -> None:
        ...


class B(A):
    def foo(self) -> None:
        self.__a()


B().foo()

[gvanrossum]

Thanks for the report -- this looks like a real bug. Fixing it would probably be fairly involved (we'd have to implement name mangling at the right level in the parser) and private members aren't that popular. So I'm classifying this as low priority.

[AlexWaygood]

Closing as a duplicate of #8267