/usr/share/doc/libmixlib-log-ruby1.8/changelog.Debian.gz is in libmixlib-log-ruby1.8 1.4.1-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libmixlib-log-ruby1.8/../ruby-mixlib-log/changelog.Debian.gz