New issue by ericonr on void-packages repository

https://github.com/void-linux/void-packages/issues/30008

Description:
`python3-3.9.3_1`

Examples:

- https://build.voidlinux.org/builders/i686_builder/builds/31605/steps/shell_3/logs/stdio
- #29744 

Just `python3 setup.py build` works, but `cython` makes it segfault.

@ahesford