anchor.diff:  , ode
   , openal
   , openssl
  -, racket
  +, racket_7_9
   , sconsPackages
   , zlib
   }:
  
positive.code:     ode
      openal
      openssl.dev
      racket
    ];
    nativeBuildInputs = [ sconsPackages.scons_3_1_2 ];
  
  
negative.code:     openssl
      zlib
    ];
    racket = racket_7_9;
  in
  stdenv.mkDerivation rec {
    pname = "fluxus";
  