I’m trying to annotate subclasses of nn.Module inline, but for now I unable to get it to work. For my project I create an abstract subclass of nn.Module
from typing import Any
from torch import nn


class Foo(nn.Module):
    def forward(self, *input: Any, **kwargs: Any) -> Any:
        pass

Running mypy 2 on this succeeds. In a second step I add a more concrete class
import torch


class Bar(Foo):
    def forward(self, input: torch.Tensor) -> torch.Tensor:
        pass

Now mypy errors with
error: Signature of "forward" incompatible with supertype "Foo"
error: Signature of "forward" incompatible with supertype "Module" 

while pointing to forward() of Bar both times. I’m aware that this is valid error since Bar violates the Liskov Substitution Principle 5. Looking at the stub of nn.Module 20 I think the marked paragraph is related, but for now I was unable to comprehend it.
But since I think it is not intended for every subclass of nn.Module to have that exact signature, I’m puzzled how to get around this. Can someone help me out here?