The duplicate base class causes the checking blocked.

example.py

class N(type):
    pass

class B(N, metaclass=N):
    pass

class D(B, B):
    pass

The expected behavior：

The error can be ignored and the checking will not be blocked.

The actual behavior：

>> mypy example.py
Desktop/example.py:7: error: Duplicate base class "B"
Found 1 error in 1 file (errors prevented further checking)

Environment

Mypy version: 1.3.0
Python version: 3.11.3
Operating System: Ubuntu 18.04
How to install MyPy: "python3.11 -m pip install mypy"