/usr/share/doc/gir1.2-poppler-0.18/changelog.Debian.gz is in gir1.2-poppler-0.18 0.41.0-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/gir1.2-poppler-0.18/../libpoppler58/changelog.Debian.gz