anchor.diff:  { stdenv
   , fetchurl
  -, python
  +, waf
   
   , gtk2
   , libsndfile
   }:
   
   stdenv.mkDerivation rec {
  -  name = "lv2-1.12.0";
  +  name = "lv2-1.14.0";
   
     src = fetchurl {
       url = "http://lv2plug.in/spec/${name}.tar.bz2";
  -    sha256 = "7a4a53138f10ed997174c8bc5a8573d5f5a5d8441aaac2de6cf2178ff90658e9";
  +    hashOutput = false;
  +    sha256 = "b8052683894c04efd748c81b95dd065d274d4e856c8b9e58b7c3da3db4e71d32";
     };
   
     nativeBuildInputs = [
  -    python
  +    waf
     ];
   
     buildInputs = [
  
positive.code:     libsndfile
    ];
  
    postPatch = ''
      patchShebangs ./waf
    '';
  
    configurePhase = ''
      ./waf configure --prefix=$out
    '';
  
    buildPhase = ''
      ./waf
    '';
  
    installPhase = ''
      ./waf install
    '';
  
    passthru = {
  
negative.code:         outputHashAlgo
          urls;
        failEarly = true;
        pgpsigUrls = map (n: "${n}.asc") src.urls;
        pgpKeyFingerprint = "907D 226E 7E13 FA33 7F01  4A08 3672 782A 9BF3 68F3";
      };
    };
  