docs: function onError (err) {
    console.error(chalk.red('✗ error:'), chalk.red(err.message))
    notifier.notify({
      title: 'Build failed:',
      message: err.message
    })
    this.emit('end')
  
    // When running without watch, process.exit(1) on error
    if (!watchifyEnabled) {
      process.exit(1)
    }
  }