anchor.diff:  
     libzbar_name =
       if stdenv.isLinux then "libzbar.so.0"
  +    else if stdenv.isDarwin then "libzbar.0.dylib"
       else "libzbar${stdenv.hostPlatform.extensions.sharedLibrary}";
   
   in
  
positive.code: }:
  
  let
    version = "4.2.0";
  
    libsecp256k1_name =
      if stdenv.isLinux then "libsecp256k1.so.0"
  
negative.code:     owner = "Groestlcoin";
      repo = "electrum-grs";
      rev = "refs/tags/v${version}";
      sha256 = "1h9r32wdn0p7br36r719x96c8gay83dijw80y2ks951mam16mkkb";
    };
  
    nativeBuildInputs = lib.optionals enableQt [ wrapQtAppsHook ];
  