Free-threaded support blockers

[nitzmahone]

The pending release of Python 3.14 removes the experimental designation from the free-threaded API. Now that Cython 3.1 has added experimental support for it, it's reasonable to start working toward support in PyYAML.

This issue is a parent issue for known blockers to shipping free-threaded support in PyYAML.

[lysnikolaou]

Hey @nitzmahone!

First of all, I'd like to apologize for the miscommunication around the fork once more. I misunderstood your earlier comments and thought the best way to help the ecosystem in the meantime was to experiment with free-threading support in a separate repository. I now see that wasn't aligned with your expectations, and I appreciate the clarification you've given since.

I have funded time allocated to work on this, and I'd be glad to assist in any way that's most helpful to you. My goal is simply to support the project and make sure PyYAML is ready for free-threading users when the time comes.

To start small, I've gone ahead and opened a PR that only upstreams some tests. Hopefully that's a good start. I see that you've self-assigned all of the issues opened on this tracker. Is that a signal that you want to work on these yourself or can I start working on those too after we're done with the tests PR?

Thanks again for your time and for taking this on! I really appreciate all the work you do maintaining PyYAML, and I'll make sure my contributions (if they're welcome) fit the workflow that's easiest for you.

[lysnikolaou]

@nitzmahone Friendly ping in case you have any spare cycles to have a look at this ☝️.

[rgommers]

I noticed that cp314t wheels were added in gh-864 and are now up on PyPI in the 6.0.3 release. That's great, thank you!

I imagine that there are tests to be added and some things to be fixed for parallel usage, but this should already unblock a lot of downstream packages which don't need true multi-threaded usage.