anchor.diff:  , pkg-config
   , autoreconfHook
   , db48
  +, sqlite
   , boost
   , zeromq
   , hexdump
  
positive.code: 
  with stdenv.lib;
  let
    version = "0.20.1";
    majorMinorVersion = versions.majorMinor version;
    desktop = fetchurl {
      url = "https://raw.githubusercontent.com/bitcoin-core/packaging/${majorMinorVersion}/debian/bitcoin-qt.desktop";
  
negative.code:     ++ optional withGui wrapQtAppsHook;
    buildInputs = [ boost zlib zeromq miniupnpc libevent ]
      ++ optionals stdenv.isLinux [ util-linux ]
      ++ optionals withWallet [ db48 sqlite ]
      ++ optionals withGui [ qtbase qttools qrencode ];
  
    postInstall = optional withGui ''
  