/usr/share/doc/libxcb-xinerama0-dbg/changelog.Debian.gz is in libxcb-xinerama0-dbg 1.11.1-1ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libxcb-xinerama0-dbg/../libxcb1/changelog.Debian.gz