/usr/share/doc/libunac1-dev/AUTHORS is in libunac1-dev 1.8.0-6ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libunac1-dev/../libunac1/AUTHORS
/usr/share/doc/libunac1-dev/../libunac1/AUTHORS