anchor.diff:  }:
   
   let
  -  version = "1.2.7";
  +  version = "1.3.1";
     inherit (stdenv.lib) optional optionals optionalString;
   in
   
  
positive.code:   meta = with stdenv.lib; {
      description = "An OpenType text shaping engine";
      homepage = http://www.freedesktop.org/wiki/Software/HarfBuzz;
      maintainers = [ maintainers.eelco ];
      platforms = with platforms; linux ++ darwin;
    };
  }
  
negative.code: 
    src = fetchurl {
      url = "http://www.freedesktop.org/software/harfbuzz/release/harfbuzz-${version}.tar.bz2";
      sha256 = "18c9rzg4ilmhbx8hpdhcjffkzq5smcbc2lr23g6fdm8rs5nj0hm2";
    };
  
    outputs = [ "out" "dev" ];
  