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