It might be a good idea to include E_COMPILE_ERROR in error_reporting. 

If you have a customer error handler that does not output warnings, you may get a white screen of death if a "require" fails.

Example:
<?php 
  error_reporting(E_ERROR | E_WARNING | E_PARSE);

  function myErrorHandler($errno, $errstr, $errfile, $errline) {
    // Do something other than output message.
    return true;
  }

  $old_error_handler = set_error_handler("myErrorHandler");

  require "this file does not exist";
?>

To prevent this, simply include E_COMPILE_ERROR in the error_reporting.

<?php
  error_reporting(E_ERROR | E_WARNING | E_PARSE | E_COMPILE_ERROR);
?>