As far as I understand, `setuptools._distutils` is just a vendored copy of `distutils`. But, right now they are different. For example: - https://github.com/python/typeshed/blob/c1a857a41a1cbc62df5c6fdac52d0ac79fdf2824/stdlib/distutils/core.pyi - https://github.com/python/typeshed/tree/c1a857a41a1cbc62df5c6fdac52d0ac79fdf2824/stubs/setuptools/setuptools/_distutils (no `core.pyi`) Here's the source code for `core.py`: - https://github.com/python/cpython/blob/3.11/Lib/distutils/core.py - https://github.com/pypa/setuptools/blob/b545fc778583f644d6c331773dbe0ea53bfa41af/setuptools/_distutils/core.py So, we need to work on them! Refs https://github.com/python/typeshed/pull/10249