private function runGitCommand($command)
    {
        $path = dirname($this->file);
        $process = new Process($command, $path);

        if (0 === $process->run()) {
            return trim($process->getOutput());
        }

        throw new RuntimeException(
            sprintf(
                'The tag or commit hash could not be retrieved from "%s": %s',
                $path,
                $process->getErrorOutput()
            )
        );
    }