anchor.diff:  { stdenv
   , fetchurl
  -, pkgconfig
  +, pkg-config
   , autoreconfHook
   , db48
   , boost
  
positive.code:     homepage = "https://bitcoin.org/";
      downloadPage = "https://bitcoincore.org/bin/bitcoin-core-${version}/";
      changelog = "https://bitcoincore.org/en/releases/${version}/";
      maintainers = with maintainers; [ roconnor ];
      license = licenses.mit;
      platforms = platforms.unix;
    };
  
negative.code:   };
  
    nativeBuildInputs =
      [ pkg-config autoreconfHook ]
      ++ optional stdenv.isDarwin hexdump
      ++ optional withGui wrapQtAppsHook;
    buildInputs = [ boost zlib zeromq miniupnpc libevent ]
      ++ optionals stdenv.isLinux [ util-linux ]
      ++ optionals withWallet [ db48 ]
      ++ optionals withGui [ qtbase qttools qrencode ];
  
    postInstall = optional withGui ''
  