Bug report

Build a debug version of CPython on Windows.
Build an an extension module linked against this debug CPython's python3_d.dll.

This crashes at runtime with the following error:

ImportError: Module use of python3_d.dll conflicts with this version of Python.

This originates from

It looks like this code doesn't account for the possibility of linking against python3_d.dll when using a debug build.

Your environment

• CPython versions tested on: main branch, 7a25310
• Operating system and architecture: Windows 12 amd64

Originally reported to me in PyO3/pyo3#2780

Linked PRs

• gh-101614: don't treat python3_d.dll as a Python dll #101615
• [3.11] gh-101614: Don't treat python3_d.dll as a Python DLL when checking extension modules for incompatibility (GH-101615) #101690
• [3.10] gh-101614: Don't treat python3_d.dll as a Python DLL when checking extension modules for incompatibility (GH-101615) #101691