/usr/bin/mpy.openmpi is in yorick-mpy-openmpi 2.2.04+dfsg1-6+b1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/bin/../lib/yorick/bin/mpy.openmpi
/usr/bin/../lib/yorick/bin/mpy.openmpi