Mostly the following PHP.ini settings are enough to make php display errors in a production environement where error_reporting & display_errors are disabled in the PHP.ini.

[pastacode lang=”php” message=”” highlight=”” provider=”manual”]

ini_set('display_startup_errors', 'On');
ini_set('display_errors', 'On');
ini_set('html_errors ', 'On');
ini_set('log_errors  ', 'On');
ini_set('error_reporting', 'E_ALL & ~E_NOTICE');
error_reporting(E_ALL);

[/pastacode]

But in some cases there will not be an error message displayed. The only solution I found was to enable the dispaly_errors in the php.ini.
To avoid setting this aparameter globally it could also be set in the conf-file for the virtual host which worked for me pritty fine.

[pastacode lang=”apacheconf” message=”” highlight=”” provider=”manual”]

:>
        ...
        php_value display_errors On
        ...

[/pastacode]