/usr/lib/ghc-doc/hoogle/libghc-sdl-gfx-doc.txt is in libghc-sdl-gfx-doc 0.6.0-11build3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-sdl-gfx-doc/html/SDL-gfx.txt