sub get_and_cache_nodes {
  my ($self, $url, $update_info)=@_;
  # $url starts "http://www.perlmonks.org/index.pl?node="
  #   . "node+query+xml+generator&nodes=47259,"...
  my $text=$self->getpage($url);
  # $text ends up "\r\n"
  if (!defined($text)) {
    warn "Error obtaining page: $@\n";
    return;
  }
  # The next regex does nothing
  $text=~s!<NODE>\s*</NODE>!!g;
  # This line causes the error:
  my $tmpxml=XMLin($text, keyattr => { AUTHOR => "+node_id",
				       NODE   => "+node_id" },
		   forcearray => [ 'AUTHOR', 'NODE' ]);