anchor.diff:      owner = "casperjs";
       repo = "casperjs";
       rev = version;
  -    sha256 = "10b25jmh9zmlp77h0p3n9d6bnl3wn4iv3h3qnsrgijfszxyh0wgw";
  +    sha256 = "187prrm728xpn0nx9kxfxa4fwd7w25z78nsxfk6a6kl7c5656jpz";
     };
   
     buildInputs = [ phantomjs python nodePackages.eslint ];
  
positive.code:   '';
  
    dontBuild = true;
  
    installPhase = ''
      mv $PWD $out
  
negative.code: { stdenv, fetchFromGitHub, phantomjs, python, nodePackages }:
  
  let version = "1.1.1";
  
  in stdenv.mkDerivation rec {
  
  