/usr/share/doc/libgd-ocaml-dev/changelog.Debian.gz is in libgd-ocaml-dev 1.0~alpha5-8build2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libgd-ocaml-dev/../libgd-ocaml/changelog.Debian.gz