Due to the integration of Xdebug 3.4.0 in PHP 8.3.14 (but also in PHP 8.4.1), the following PHP script causes a segmentation fault of the Apache server process when the script is ending:

<?php
echo "bla";
$fasel = &$_GET;
register_shutdown_function(function () { echo "shutdown"; });

[Tue Dec 03 12:27:02.721336 2024] [core:notice] [pid 8081:tid 8081] AH00052: child pid 8162 exit signal Segmentation fault (11)

It does not matter whether an active debugger session is running or not. It is important that both the assignment of a reference to a superglobal and the registration of a shutdown function must be present in the PHP script.

Aufgefallen ist es mir zurerst in einer PHP 8.4.1 und Xdebug 3.4.0 Umgebung. Das entfernen des Xdebug-Extension hatte das Problem behoben. Genauso hat es sich mit einer PHP 8.3.14 und Xdebug 3.4.0 verhalten. Ein PHP 8.3.14 und Xdebug 3.3.2 zeigt das Problem nicht.

I first noticed it in a PHP 8.4.1 and Xdebug 3.4.0 environment. Removing the Xdebug extension solved the problem. The same happened with PHP 8.3.14 and Xdebug 3.4.0. A PHP 8.3.14 and Xdebug 3.3.2 does not show the problem.