/usr/lib/ghc-doc/hoogle/xdg-basedir.txt is in libghc-xdg-basedir-doc 0.2.2-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-xdg-basedir-doc/html/xdg-basedir.txt