If I run mypy on the following code:

class Base:
    value = 123

    @property
    def x(self) -> int:
        return self.value

    @x.setter
    def x(self, value: int) -> None:
        self.value = value

class Sub(Base):
    @property
    def x(self) -> bool:
        return self.value != 0
    
    @x.setter
    def x(self, value: int) -> None:
        self.value = value

It reports:

error: Signature of "x" incompatible with supertype "Base"  [override]

I'd expect mypy to not report any error, as bool is a subtype of int and therefore the property type returned by the subclass always conforms to the property type defined in the superclass.

This problem only occurs for writable properties: if I remove the setter definitions from both the superclass and the subclass, no false positive is reported.

I can produce this problem using mypy 0.991 on Python 3.10.8. When using mypy 0.981 instead, no false positive is reported.