anchor.diff:  
     meta = {
       homepage = "http://www.erlang.org/";
  +    downloadPage = "http://www.erlang.org/download.html";
       description = "Programming language used for massively scalable soft real-time systems";
   
       longDescription = ''
  
positive.code:   postInstall = let
      manpages = fetchurl {
        url = "http://www.erlang.org/download/otp_doc_man_${version}.tar.gz";
        sha256 = "0wsnp7sp21ydinwkg3rkazyrs382pdzwra9apikkhs70dv1hwkz4";
      };
    in ''
      ln -s $out/lib/erlang/lib/erl_interface*/bin/erl_call $out/bin/erl_call
  
negative.code: stdenv.mkDerivation rec {
    name = "erlang-" + version + "${optionalString odbcSupport "-odbc"}"
    + "${optionalString javacSupport "-javac"}";
    version = "18.2";
  
    src = fetchurl {
      url = "http://www.erlang.org/download/otp_src_${version}.tar.gz";
      sha256 = "1l1zzf245w1abiylll8pjm0pppqwvvw4fihknqkcybkx62n2ipj3";
    };
  
    buildInputs =
  