anchor.diff:  
     doCheck = true;
   
  -  meta = {
  +  meta = with stdenv.lib; {
       description = "Tool to analyze the control flow of C programs";
   
       longDescription = ''
  
positive.code: { stdenv, fetchurl, gettext, emacs }:
  
  stdenv.mkDerivation rec {
    name = "cflow-1.4";
  
    src = fetchurl {
      url = "mirror://gnu/cflow/${name}.tar.bz2";
      sha256 = "1jkbq97ajcf834z68hbn3xfhiz921zhn39gklml1racf0kb3jzh3";
    };
  
    patchPhase = ''
  
negative.code:       produced flowcharts in Emacs.
      '';
  
      license = licenses.gpl3Plus;
  
      homepage = http://www.gnu.org/software/cflow/;
  
      maintainers = [ maintainers.vrthra ];
  
      /* On Darwin, build fails with:
  
  