Bug Report

The following code is reported as error by mypy 0.930 (Python 3.8). It seems correct, and was considered correct so far:

from enum import Enum

class PyFormat(str, Enum):
    __module__ = "psycopg.adapt"
    AUTO = "s"
    TEXT = "t"
    BINARY = "b"

The error reported is:

$ mypy test_mypy.py 
test_mypy.py:4: error: Cannot override writable attribute "__module__" with a final one  [misc]

which I don't even know what means...