# File bin/el4r-instance, line 763
    def el4r_wait_expr
      @last_error = nil
      el4r_with_call {
        lispexpr = nil
        begin
          result = el4r_get
          el4r_debug { "Result: <#{result.inspect}>"; }
          lispexpr = el4r_ruby2lisp(result)
        rescue ELError
          el4r_debug { "Passing lisp error: #{ErrorUtils.stacktrace_message($!)}"; }
          lispexpr = "(el4r-signal-last-error)"
        rescue StandardError, ScriptError
          @last_error or
            el4r_log("Error: #{ErrorUtils.stacktrace_message($!)}")
          @last_error = $!
          lispexpr = "(signal 'el4r-ruby-error nil)"
        end
        el4r_send(lispexpr)
      }
    end