Pytest crashes on cp314-musllinux_x86_64

[vytas7]

Hello!
Not sure if this is an issue in CPython 3.14.0b4, the musllinux toolchain, Pytest, Cibuildwheel, or a combination thereof, so thought starting this as a discussion first.

Running the following inside falcon's source tree successfully builds the musllinux wheel, but then the subsequent attempt to run pytest ends up in a crash:

CIBW_ENABLE=cpython-prerelease CIBW_BUILD=cp314-musllinux_x86_64 cibuildwheel

An example from the CI: https://github.com/falconry/falcon/actions/runs/16298614592/job/46027010425.
(I can reproduce the same issue running cibuildwheel 3.12 on my machine as well.)

The manylinux toolchain seems to work fine.

[vytas7]

It seems it is something with Cython and compilation under 3.14 & musllinux:

Fatal Python error: _Py_CheckRecursiveCall: Unrecoverable stack overflow (used 298 kB) while calling a Python object
Python runtime state: initialized

Note that PyPA's musllinux container still seems to be running Python 3.14.0b3. Shouldn't it have been updated to 3.14.0b4?

[vytas7]

Sorry for the spam, it seems to be a variation of cython/cython#4272.
So the only change was that for some reason PyPA musllinux containers for 3.14 have even tighter stack size limits than before. 🤔