/usr/share/apport/package-hooks/source_libxkbui.py is in xserver-xorg 1:7.7+19ubuntu7.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/apport/package-hooks/source_xorg.py
/usr/share/apport/package-hooks/source_xorg.py