anchor.diff:  { stdenv
   , fetchurl
  -, findXMLCatalogs
  -, flex
   , makeWrapper
   
  +, findXMLCatalogs
   , getopt
  -, libxml2
   }:
   
   stdenv.mkDerivation rec {
  
positive.code:     done < <(./configure --help 2>&1 | awk '{ if (/[A-Z][ ]*Name/) { print "export " $1 "=\"$(type -P " tolower($1) ")\""; } }')
    '';
  
    meta = with stdenv.lib; {
      description = "Front-end to an XSL toolchain";
      homepage = https://pagure.io/xmlto;
  
negative.code:   };
  
    buildInputs = [
      getopt.bin
    ];
  
    # When using xmlto, it needs the ability to set the environment variables
  