/usr/share/doc/libmcs-dev/changelog.Debian.gz is in libmcs-dev 0.7.2-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libmcs-dev/../libmcs1/changelog.Debian.gz
/usr/share/doc/libmcs-dev/../libmcs1/changelog.Debian.gz