protected function getRootOption(): string
    {
        $option = '';
        // if root is set
        if (!empty($this->repositoryRoot)) {
            // and it's not the current working directory
            if (getcwd() !== $this->repositoryRoot) {
                $option = ' -C ' . escapeshellarg($this->repositoryRoot);
            }
        }
        return $option;
    }