/usr/share/man/man1/mpif90.mpich.1.gz is in libmpich-dev 3.2-7+b1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/man/man1/mpifort.mpich.1.gz
/usr/share/man/man1/mpifort.mpich.1.gz