Heads up: 3.13.5 release coming soon

[steve.dower]

Just letting everyone know that due to a regression on Windows, we’ll be making the 3.13.5 release very soon (fingers crossed early next week).

If you know of any other problems in 3.13.4 that ought to be resolved quickly, do let us know and we should be able to get them in for next week.^[1]

For reference, the Windows issue is that the pyconfig.h in the regular installer (not on Nuget or PyManager) is set to always enable free-threaded builds. This causes normal builds to fail, and due to how the preprocessor variables are set up, it can only be disabled by patching the pyconfig.h header. After the fix, 3.13 will be consistent with 3.14+ (the Py_GIL_DISABLED variable must always be specified when compiling extensions), which was basically how it was before and most build backends already handle this correctly.

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1. That way it won’t look as much like my fault ↩︎

[mwichmann (Mats Wichmann)]

@steve.dower

For reference, the Windows issue is that the pyconfig.h in the regular installer (not on Nuget or PyManager) is set to always enable free-threaded builds. This causes normal builds to fail, and due to how the preprocessor variables are set up, it can only be disabled by patching the pyconfig.h header.

Wow, I just ran into this and thought I was going crazy… testsuite on our project does some things with Swig, which uses sysconfig to fish out the paths needed, and suddenly got LINK : fatal error LNK1004: cannot open file 'python313t.lib' when nothing was asking for freethreaded… had no idea what was going on. Thanks for finding and turning around a fix so quickly!