message: Report time only above a certain threshold.
diff: @@ -1869,6 +1869,7 @@ def command_flatten(command, env = None):
  return env_ + ' '.join(pipes.quote(str(a)) for a in command)
  NO_TIME_REPORTS = env('NO_TIME_REPORTS') is not None
  +TIME_REPORT_THRESHOLD = int(env('TIME_REPORT_THRESHOLD', '30'))
  @contextlib.contextmanager
  def log_time(runner):
  @@ -1893,7 +1894,9 @@ def log_time(runner):
  timer[0].cancel()
  end_time = time.time()
  if not NO_TIME_REPORTS:
  - print('Ran {} in {}'.format(runner, duration(start_time, end_time)))
  + d = duration(start_time, end_time)
  + if TIME_REPORT_THRESHOLD is None or d.seconds > TIME_REPORT_THRESHOLD:
  + print('Ran {} in {}'.format(runner, d))
  class Builder:
  