/usr/share/doc/libmadlib-dbg/changelog.Debian.gz is in libmadlib-dbg 1.3.0-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libmadlib-dbg/../libmadlib/changelog.Debian.gz
/usr/share/doc/libmadlib-dbg/../libmadlib/changelog.Debian.gz