anchor.diff:      gtkmm_2
       jack2_lib
       ladspaH
  -    librdf
  +    lrdf
       librsvg
       libsndfile
       lilv
  
positive.code:     "--no-faust"
    ] ++ optional optimizationSupport "--optimization";
  
    NIX_CFLAGS_COMPILE = [
      "-I${eigen}/include/eigen3"
    ];
  
    configurePhase = ''
        ./waf configure --prefix=$out $configureFlags
      '';
  
    buildPhase = ''
      ./waf build
  
negative.code:   inherit (stdenv.lib)
      optional;
  in
  stdenv.mkDerivation rec {
    name = "guitarix-${version}";
    version = "0.35.1";
  