/usr/share/doc/libtuxcap4.0-dbg/changelog.Debian.gz is in libtuxcap4.0-dbg 1.4.0.dfsg2-2.3build2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libtuxcap4.0-dbg/../libtuxcap4.0/changelog.Debian.gz