/usr/share/doc/libslang2-dev/changelog.Debian.gz is in libslang2-dev 2.2.4-3ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libslang2-dev/../libslang2/changelog.Debian.gz
/usr/share/doc/libslang2-dev/../libslang2/changelog.Debian.gz