Is there a way to check return type error incompatible with supertype?

[HeliWang]

For such an example:

from abc import ABCMeta, abstractmethod
from typing import Callable, Type, TypeVar, Any

class A(metaclass=ABCMeta):
    @abstractmethod
    def foo(self, x: int) -> Any: pass

    @abstractmethod
    def bar(self) -> str: pass

class B(A):
    def foo(self, x: int) -> None: ...
    def bar(self) -> int:
        return 1

#a = A()  # Error: A is abstract
b = B()  # OK

Mypy will complain the following error:
a.py:13: error: Return type of "bar" incompatible with supertype "A"

However pytype seems to ignore such an error.
Is there a way to check return type error incompatible with supertype? Thanks.

[martindemello]

No, we currently just check that classes with abstract methods are not being instantiated.

[martindemello]

this should now work with the --overriding-return-type-checks flag, and should soon be enabled by defalut.