anchor.diff:    buildInputs = [fontforge perl FontTTF];
   
     unicodeData = fetchurl {
  -    url = http://www.unicode.org/Public/6.1.0/ucd/UnicodeData.txt ;
  -    sha256 = "1bd6zkzvxfnifrn5nh171ywk7q56sgk8gdvdn43z9i53hljjcrih";
  +    url = http://www.unicode.org/Public/9.0.0/ucd/UnicodeData.txt ;
  +    sha256 = "13zfannnr6sa6s27ggvcvzmh133ndi38pfyxsssvjmw2s8ac9pv8";
     };
     blocks = fetchurl {
  -    url = http://www.unicode.org/Public/6.1.0/ucd/Blocks.txt;
  -    sha256 = "0w0vkb09nrlc6mrhqyl9npszdi828afgvhvlb1vs5smjv3h8y3dz";
  +    url = http://www.unicode.org/Public/9.0.0/ucd/Blocks.txt;
  +    sha256 = "04xyws1prlcnqsryq56sm25dlfvr3464lbjjh9fyaclhi3a2f8b1";
     };
   
  -  src = fetchurl {
  -    url = "mirror://sourceforge/dejavu/dejavu-fonts-${version}.tar.bz2";
  -    sha256 = "1xdbi4llrq1qbkd73352ibrfqcbz93dww8hab216qz5szd95yvv4";
  +  src = fetchFromGitHub {
  +    owner = "dejavu-fonts";
  +    repo = "dejavu-fonts";
  +    rev = "version_${stdenv.lib.replaceStrings ["."] ["_"] version}";
  +    sha256 = "1xknlg2h287dx34v2n5r33bpcl4biqf0cv7nak657rjki7s0k4bk";
     };
   
     buildFlags = "full-ttf";
  
positive.code:   '';
  
    meta = {
      platforms = stdenv.lib.platforms.linux;
    };
  }
  
negative.code: {fetchurl, fetchFromGitHub, stdenv, fontforge, perl, fontconfig, FontTTF}:
  
  let version = "2.37" ; in
  
  stdenv.mkDerivation rec {
    name = "dejavu-fonts-${version}";
  