anchor.diff:  
     nativeBuildInputs = [ perl ];
   
  -  buildInputs = [ pcre zlib libjpeg ];
  +  buildInputs = [ zlib libjpeg ];
   
     postPatch = ''
       patchShebangs qpdf/fix-qdf
  
positive.code:   meta = with stdenv.lib; {
      homepage = http://qpdf.sourceforge.net/;
      description = "A C++ library and set of programs that inspect and manipulate the structure of PDF files";
      license = licenses.artistic2;
      maintainers = with maintainers; [ abbradar ];
      platforms = platforms.all;
    };
  
negative.code: { stdenv, fetchurl, libjpeg, zlib, perl }:
  
  let version = "7.0.0";
  in
  