anchor.diff:  , fetchFromGitHub
   , openssl
   , boost
  +, libb2
   , libevent
   , autoreconfHook
   , db4
  
positive.code: stdenv.mkDerivation rec {
  
    pname = "bitcoin" + toString (optional (!withGui) "d") + "-gold";
    version = "0.15.2";
  
    src = fetchFromGitHub {
      owner = "BTCGPU";
      repo = "BTCGPU";
      rev = "v${version}";
      sha256 = "0grd1cd8d2nsrxl27la85kcan09z73fn70ncr9km4iccaj5pg12h";
    };
  
    nativeBuildInputs = [
  
negative.code:     db4
      zeromq
      libsodium
      libb2
    ] ++ optionals withGui [
      qtbase
      qttools
  