PHPDbg misidentifies uncaught exception when exception is not yet loaded

Description

The following code:

<?php declare(strict_types=1);

try {
    throw new RuntimeException();
} catch (LibrarySpecificException) {
    // A library specific exception. Not autoloaded since it did not happen.
} catch (RuntimeException) {
    echo "Caught it. 'handled' it\n";
}

When run via php or phpdbg -qrr Resulted in this output:

Caught it. 'handled' it

But when run via phpdbg -r resulted in output:

[Welcome to phpdbg, the interactive PHP debugger, v8.5.6]
To get help using phpdbg type "help" and press enter
[Please report bugs to <https://github.com/php/php-src/issues>]
[PHP Fatal error:  During class fetch: Uncaught RuntimeException in /src/demo.php:4
Stack trace:
#0 {main} in /src/demo.php on line 4
Stack trace:
#0 {main}]
>00004:     throw new RuntimeException();
 00005: } catch (LibrarySpecificException) {
 00006:     // A library specific exception. Not autoloaded since it did not happen.
prompt> 

PHP Version

PHP 8.5.6 (cli) (built: May  8 2026 16:44:06) (NTS)
Copyright (c) The PHP Group
Built by https://github.com/docker-library/php
Zend Engine v4.5.6, Copyright (c) Zend Technologies
    with Zend OPcache v8.5.6, Copyright (c), by Zend Technologies


PHP 8.4.20 (cli) (built: Apr  8 2026 08:16:38) (NTS gcc x86_64)
Copyright (c) The PHP Group
Built by Amazon Linux
Zend Engine v4.4.20, Copyright (c) Zend Technologies
    with Zend OPcache v8.4.20, Copyright (c), by Zend Technologies

Operating System

Alpine3.22 and Amazon Linx 2023

Reproduisez le script fourni avec phpdbg -r et phpdbg -qrr, en les comparant à php. Commencez par le chemin d’exécution de phpdbg impliqué dans la récupération des classes et la gestion des exceptions ; c’est terminé lorsque l’invocation avec -r reconnaît systématiquement la RuntimeException non interceptée et préserve le comportement attendu de catch.