There's a closed pull request on the void-packages repository

[wip] pari: add config options
https://github.com/void-linux/void-packages/pull/29635

Description:
This is such that pari is usable when building sagemath, which requires pthread.

Note: pthread also sets --enable-tls (build the thread-safe version of the library). This tends to slow down the shared library libpari.so by about 25%, so it is suggested to use the static library libpari.a instead. How do I do that?
Arch Linux has `export CFLAGS+=' -flto'`, Alpine has `export CFLAGS="$CFLAGS -flto" # reduce speed losses under pthread`.