    # 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