anchor.diff:  { stdenv, fetchurl, ghostscript, perl, groff }:
   
   stdenv.mkDerivation rec {
  -  name = "groff-1.20.1";
  +  name = "groff-1.22.2";
   
     src = fetchurl {
       url = "mirror://gnu/groff/${name}.tar.gz";
  -    sha256 = "01fq5i68p4s4fc6m8i90y5d28wk1x6zh2mkw85n0qqnb6n0qfidn";
  +    sha256 = "0xi07nhj5vdgax37rj25mwxzdmsz1ifx50hjgc6hqbkpqkd6821q";
     };
   
     buildInputs = [ ghostscript ];
  
positive.code:       version gxditview of the X11 xditview previewer, and an
        implementation of the -mm macros.
      '';
  
      homepage = http://www.gnu.org/software/groff/;
  
      license = "GPLv3+";
    };
  }
  
negative.code:   };
  
    meta = {
      homepage = "http://www.gnu.org/software/groff/";
      description = "GNU Troff, a typesetting package that reads plain text and produces formatted output";
      license = "GPLv3+";
  
      longDescription = ''
        groff is the GNU implementation of troff, a document formatting
  