Bug report

Bug description:

Hello,

I tried to build a C-extension locally with python 3.13a4 and got the errorLINK : fatal error LNK1104: cannot open file 'python313t.lib'.

(I got Python 3.13a4 from the python.org installer, tested Windows 32 and 64 bit).

After trying to install the free threaded builds using the new installer option, trying to build using those, and then installing everything fresh, I found that ininclude/pyconfig.h, there is a line#define Py_GIL_DISABLED 1. This line causes the compiler to look for python313t.lib instead of python313.lib, and commenting it out fixed the build.

It seems to me that the non-freethreaded build is shipping out with the wrong pyconfig.h setup.

This was reported by Pillow here:python-pillow/Pillow#7805

They linked it to#115545, but I think that may be a different issue? The interpreters launch fine from the python.org install, they just don't seem to work for building C-extensions with.

Thank you.

CPython versions tested on:

3.13

Operating systems tested on:

Windows

Linked PRs

• gh-115582: Make default PC/pyconfig.h work for free-threaded builds with manual /DPy_GIL_DISABLED #115850