New comment by tornaria on void-packages repository

https://github.com/void-linux/void-packages/pull/34030#issuecomment-1000496931

Comment:
Otherwise, you can try to patch `Integer.factorial` to print out some debug information, like the `self` and `z.value` right after the call to `PY_NEW()`. I wonder if for some reason `PY_NEW(Integer)` is failing and it's returning 0. This would give a segfault since I think `mpz_fac_ui` assumes its arguments are non-null.