/usr/share/doc/compiz-plugins-main-default/changelog.Debian.gz is in compiz-plugins-main-default 1:0.9.13.1+18.04.20180302-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/compiz-plugins-main-default/../compiz-core/changelog.Debian.gz