anchor.diff:    };
   
     buildInputs = [ geoclue ]
  -    ++ stdenv.lib.optionals guiSupport [ python pygobject3 pyxdg ]
  +    ++ stdenv.lib.optionals guiSupport [ gtk3 python pygobject3 pyxdg ]
       ++ stdenv.lib.optionals drmSupport [ libdrm ]
       ++ stdenv.lib.optionals randrSupport [ libxcb ]
       ++ stdenv.lib.optionals vidModeSupport [ libX11 libXxf86vm ];
  
positive.code:   '';
  
    postInstall = stdenv.lib.optionalString guiSupport ''
      wrapProgram "$out/bin/redshift-gtk" --prefix PYTHONPATH : "$PYTHONPATH"
    '';
  
    meta = with stdenv.lib; {
  
negative.code: { fetchurl, stdenv, gettext, intltool, pkgconfig, makeWrapper
  , geoclue, python, pygobject3, gtk3, pyxdg
  , libdrm, libX11, libxcb, libXxf86vm
  , guiSupport ? true
  , drmSupport ? true
  