/usr/share/doc/libgeant321-2-dev/changelog.Debian.gz is in libgeant321-2-dev 1:3.21.14.dfsg-11.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libgeant321-2-dev/../libgeant321-2-gfortran/changelog.Debian.gz