anchor.diff:  
   # All modules can be enabled by choosing 'all_modules'.
   # we include here the DCE mandatory ones
  -, modules ? [ "core" "network" "internet" "point-to-point" "fd-net-device" "netanim"]
  +, modules ? [ "core" "network" "internet" "point-to-point" "point-to-point-layout" "fd-net-device" "netanim" ]
   , lib
   }:
   
  
positive.code: 
    postPatch = ''
      patchShebangs doc/ns3_html_theme/get_version.sh
    '';
  
    wafConfigureFlags = with stdenv.lib; [
  
negative.code: in
  stdenv.mkDerivation rec {
    pname = "ns-3";
    version = "32";
  
    src = fetchFromGitLab {
      owner = "nsnam";
      repo   = "ns-3-dev";
      rev    = "ns-3.${version}";
      sha256 = "158yjhsrmslj1q4zcq5p16hv9i82qnxx714l7idicncn0wzrfx7k";
    };
  
    nativeBuildInputs = [ wafHook ];
  