/usr/lib/ghc-doc/hoogle/libghc-xmonad-contrib-doc.txt is in libghc-xmonad-contrib-doc 0.12-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-xmonad-contrib-doc/html/xmonad-contrib.txt