code: def spawn(opts, conf):
      
      if opts.config is not None:
          os.environ["CALLSIGN_CONFIG_FILE"] = opts.config
      sys.argv[1:] = [
          "-noy", sibpath(__file__, "callsign.tac"),
          "--pidfile", conf['pidfile'],
          "--logfile", conf['logfile'],
      ]
      twistd.run()
docs: Acts like twistd