/usr/share/doc/libxmmsclient-glib-dev/changelog.Debian.gz is in libxmmsclient-glib-dev 0.8+dfsg-18.1build3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libxmmsclient-glib-dev/../libxmmsclient6/changelog.Debian.gz