/usr/share/doc/gap/changelog-4.2.Debian.gz is in gap 4r7p9-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/gap/../gap-libs/changelog-4.2.Debian.gz
/usr/share/doc/gap/../gap-libs/changelog-4.2.Debian.gz