The following variables are undefined
https://github.com/phpbb/phpbb/blob/ed9cbc89c19bc6321bfdd540f241683b71ea9a6e/phpBB/develop/benchmark.php#L143
https://github.com/phpbb/phpbb/blob/ed9cbc89c19bc6321bfdd540f241683b71ea9a6e/phpBB/develop/benchmark.php#L343