codeguy/php-the-right-way — pull request #164 by gerardroche (2012-08-08 06:07:40+00:00)
Title: error_reporting can be set to -1 in dev env

"Passing in the value -1 will show every possible error, even when new levels and constants are added in future PHP versions. The E_ALL constant also behaves this way as of PHP 5.4."

http://php.net/manual/en/function.error-reporting.php