anchor.diff:  
   # TODO: Wayland support
   # TODO: investigate libquvi support: it isn't detected by Waf script!
  +# TODO: investigate lua sockets problem
   # TODO: investigate caca support: it isn't detected by Waf script!
   # TODO: a more systematic way to test this package
  
positive.code: assert quviSupport -> libquvi != null;
  assert cacaSupport -> libcaca != null;
  
  # Purity problem: Waf needed to be is downloaded by bootstrap.py
  # but by purity reasons it should be avoided; thanks the-kenny to point it out!
  # Now, it will just download and package Waf, mimetizing bootstrap.py behaviour
  
  let
    waf = fetchurl {
      url = https://waf.googlecode.com/files/waf-1.7.13;
      sha256 = "03cc750049350ee01cdbc584b70924e333fcc17ba4a2d04648dab1535538a873";
    };
  
    version = "0.3.7";
  
negative.code:   };
  
    buildInputs = with stdenv.lib;
      [ waf freetype pkgconfig ffmpeg libass docutils which libpthreadstubs lua5_sockets ]
      ++ optionals x11Support [ libX11 libXext mesa libXxf86vm ]
      ++ optional alsaSupport alsaLib
      ++ optional xvSupport libXv
  