private function findRootDir()
    {
        $configFile = 'hidev.yml';
        for ($i = 0; $i < 9; ++$i) {
            if (file_exists($configFile)) {
                return getcwd();
            }
            chdir('..');
        }
        throw new InvalidParamException("Not a hidev project (or any of the parent directories).\nUse `hidev init` to initialize hidev project.");
    }