Binary (windows?) wheels for 3.15 are probably incompatible with newly-released 3.15b4; perhaps a 3.15b4 incompatibility in general

[jamadden]

Over in this cython bug I documented a case where binary wheels that worked in 3.15b3 failed in 3.15b4, which came out this weekend.

I can't prove it, but I'm pretty sure CFFI's wheels are in the same situation. I believe this because, without any related code changes on gevent's part, our Windows builds that worked correctly on 3.15b3 suddenly started segfaulting in nearly every test on 3.15b4.

There is some additional information. Even, after I started building CFFI from scratch on mac/linux (pip install --no-binary=:all: cffi), I was seeing one crash on 3.15 that appears related to CFFI. That's the only test I had that uses CFFI (the Windows tests all use CFFI), and when I disabled that test, the crashes went away, so I think we can rule out gevent or 3.15b4 itself.

[mattip]

Are you set up to run your tests under a debugger on those platforms? Typically that kind of issue crops up when an application's cffi-allocated variable is not held in the interpreter and the GC collects the buffer while something else is accessing that buffer. It would help if you could cut the failure down to a small reproducer.