/usr/include/x86_64-linux-gnu/pari/genpari.h is in libpari-dev 2.7.5-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/include/x86_64-linux-gnu/pari/pari.h
/usr/include/x86_64-linux-gnu/pari/pari.h