/usr/share/doc/libprojectm-qt1v5/changelog.Debian.gz is in libprojectm-qt1v5 2.1.0+dfsg-4build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libprojectm-qt1v5/../libprojectm2v5/changelog.Debian.gz