The new version of python from arch breaks the ABI and leads to segfault when using many packages, such as cython or aiohttp. Regular arch is not affected as it is a problem for 32-bit systems (in our case for armv6h and armv7h). 3.9.4 contains a hotfix for this. Please downgrade the package to 3.9.2 or upgrade to 3.9.4. I've tested 3.9.4 and it works.
https://docs.python.org/release/3.9.4/w ... #changelog