anchor.diff:      udunits2 = [ pkgs.udunits pkgs.expat ];
       V8 = [ pkgs.v8_3_14 ];
       VBLPCM = [ pkgs.gsl_1 ];
  -    VBmix = [ pkgs.gsl_1 pkgs.fftw pkgs.qt4 ];
       WhopGenome = [ pkgs.zlib.dev ];
       XBRL = [ pkgs.zlib pkgs.libxml2.dev ];
       xml2 = [ pkgs.libxml2.dev ] ++ lib.optionals stdenv.isDarwin [ pkgs.perl ];
  
positive.code:     "EasyqpcR"
      "EcoVirtual"
      "ENiRG"
      "EnQuireR"
      "eVenn"
      "exactLoglinTest"
      "fat2Lpoly"
  
negative.code:     RGtk2 = [ pkgs.pkgconfig ];
      RProtoBuf = [ pkgs.pkgconfig ];
      Rpoppler = [ pkgs.pkgconfig ];
      XML = [ pkgs.pkgconfig ];
      cairoDevice = [ pkgs.pkgconfig ];
      chebpol = [ pkgs.pkgconfig ];
  