/usr/share/doc/kdelibs5-experimental-dev/changelog.Debian.gz is in kdelibs5-experimental-dev 4:4.8.2-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/kdelibs5-experimental-dev/../libkdecore5/changelog.Debian.gz