/usr/lib/ghc-doc/hoogle/libghc-gtk-doc.txt is in libghc-gtk-doc 0.13.9-3build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-gtk-doc/html/gtk.txt
/usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-gtk-doc/html/gtk.txt