/usr/share/doc/libogre-1.9.0-dbg/changelog.Debian.gz is in libogre-1.9.0-dbg 1.9.0+dfsg1-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libogre-1.9.0-dbg/../libogre-1.9.0/changelog.Debian.gz