some debugging

src/test.php

@@ -0,0 +1,23 @@
+<?php
+declare(strict_types=1);
+
+namespace App;
+
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+use Symfony\Component\HttpKernel\Event\ExceptionEvent;
+use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
+use Symfony\Component\HttpKernel\KernelEvents;
+
+class test implements EventSubscriberInterface
+{
+
+    public static function getSubscribedEvents()
+    {
+        return [KernelEvents::EXCEPTION => 'x'];
+    }
+
+    public function x(ExceptionEvent $event)
+    {
+        dd($event->getThrowable());
+    }
+}