/usr/lib/ghc-doc/hoogle/fclabels.txt is in libghc-fclabels-doc 1.1.4.3-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-fclabels-doc/html/fclabels.txt