anchor.diff:      homepage = http://www.bitcoin.org/;
       maintainers = with maintainers; [ roconnor AndersonTorres ];
       license = licenses.mit;
  -    # bitcoin needs hexdump to build, which doesn't seem to build on darwin at the moment.
  -    platforms = platforms.linux;
  +    platforms = platforms.unix;
     };
   }
  
positive.code: 
    nativeBuildInputs =
      [ pkgconfig autoreconfHook ]
      ++ optional withGui wrapQtAppsHook;
    buildInputs = [ openssl db48 boost zlib zeromq
                    miniupnpc libevent]
  
negative.code: { stdenv, fetchurl, pkgconfig, autoreconfHook, openssl, db48, boost, zeromq, rapidcheck, hexdump
  , zlib, miniupnpc, qtbase ? null, qttools ? null, wrapQtAppsHook ? null, utillinux, python3, qrencode, libevent
  , withGui }:
  
  