Issue #3258048: Ensure the stage is marked as available even all stage directories can't be deleted

package_manager/tests/src/Kernel/StageOwnershipTest.php

@@ -284,11 +284,13 @@ class StageOwnershipTest extends PackageManagerKernelTestBase {
 
     // Listen to the post-destroy event so we can confirm that it was fired, and
     // the stage was made available, despite the file system error.
+    $stage_available = NULL;
     $this->container->get('event_dispatcher')
-      ->addListener(PostDestroyEvent::class, function (PostDestroyEvent $event): void {
-        $this->assertTrue($event->getStage()->isAvailable());
+      ->addListener(PostDestroyEvent::class, function (PostDestroyEvent $event) use (&$stage_available): void {
+        $stage_available = $event->getStage()->isAvailable();
       });
     $stage->destroy();
+    $this->assertTrue($stage_available);
   }
 
 }