protected function getInstallTask() {
    return $this->taskDrushStack($this->config('bin.drush'))
      ->arg("--root={$this->root()}/build")
      ->siteName($this->config('site.name'))
      ->siteMail($this->config('site.mail'))
      ->locale($this->config('site.locale'))
      ->accountMail($this->config('account.mail'))
      ->accountName($this->config('account.name'))
      ->accountPass($this->config('account.password'))
      ->dbPrefix($this->config('database.prefix'))
      ->dbUrl(sprintf("mysql://%s:%s@%s:%s/%s",
        $this->config('database.user'),
        $this->config('database.password'),
        $this->config('database.host'),
        $this->config('database.port'),
        $this->config('database.name')));
  }