/usr/share/doc/ruby-mapscript/changelog.Debian.gz is in ruby-mapscript 6.4.1-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/ruby-mapscript/../libmapserver1/changelog.Debian.gz
/usr/share/doc/ruby-mapscript/../libmapserver1/changelog.Debian.gz