code: func (w *Watcher) eagerRebuildEnabled() bool {
  	return Config.BoolDefault("mode.dev", true) &&
  		Config.BoolDefault("watch", true) &&
  		Config.StringDefault("watch.mode", "normal") == "eager"
  }
docs: // If watch.mode is set to eager, the application is rebuilt immediately
  // when a source file is changed.
  // This feature is available only in dev mode.