anchor.diff:  
     src = fetchurl {
       url = "mirror://gnome/sources/gtkmm/${ver_maj}/${name}.tar.xz";
  -    sha256 = "036xn22jkaf3akpid7w23b8vkqa3xxqz93mwacmyar5vw7slm3cv";
  +    sha256 = "829fa113daed74398c49c3f2b7672807f58ba85d0fa463f5bc726e1b0138b86b";
     };
   
     nativeBuildInputs = [ pkgconfig ];
  +  buildInputs = [ epoxy ];
   
     propagatedBuildInputs = [ glibmm gtk3 atkmm cairomm pangomm ];
   
     enableParallelBuilding = true;
     doCheck = true;
   
  -  meta = {
  +  meta = with stdenv.lib; {
       description = "C++ interface to the GTK+ graphical user interface library";
   
       longDescription = ''
  
positive.code: 
      homepage = http://gtkmm.org/;
  
      license = stdenv.lib.licenses.lgpl2Plus;
  
      maintainers = with stdenv.lib.maintainers; [ raskin urkud vcunat ];
      platforms = stdenv.lib.platforms.unix;
    };
  }
  
negative.code: { stdenv, fetchurl, pkgconfig, gtk3, glibmm, cairomm, pangomm, atkmm, epoxy }:
  
  let
    ver_maj = "3.18";
    ver_min = "0";
  in
  stdenv.mkDerivation rec {
  