/usr/share/doc/libdune-common-dbg/changelog.Debian.gz is in libdune-common-dbg 2.2.1-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libdune-common-dbg/../libdune-common-2.2.1/changelog.Debian.gz