If phpinfo() is disabled and debug is enabled, it throws this error
[phpBB Debug] PHP Notice: in file [ROOT]/includes/acp/acp_php_info.php on line 55: Undefined offset: 0
It is better on 3.1 because rest of the page is displayed, but I think it should be solved.
if (empty($phpinfo) || empty($output))
if (empty($phpinfo) || empty($output) || empty($output))