This is an example on how to control PHP error logging in a virtual host site for development and debugging. Assumptions
<VirtualHost *:80>
ServerName example.com
DocumentRoot /var/www/domains/example.com/html
ErrorLog /var/www/domains/example.com/apache.error.log
CustomLog /var/www/domains/example.com/apache.access.log common
php_flag log_errors on
php_flag display_errors on
php_value error_reporting 2147483647
php_value error_log /var/www/domains/example.com/php.error.log
</VirtualHost>
Note: The Virtual Host configuration is for development only because the display_errors is enabled and you do not want that in production.