Issue #3266092: Make sure staging root is unique for each Drupal site

tests/src/Kernel/ReadinessValidation/StagedDatabaseUpdateValidatorTest.php

@@ -5,6 +5,7 @@ namespace Drupal\Tests\automatic_updates\Kernel\ReadinessValidation;
 use Drupal\package_manager\Exception\StageValidationException;
 use Drupal\package_manager\ValidationResult;
 use Drupal\Tests\automatic_updates\Kernel\AutomaticUpdatesKernelTestBase;
+use Drupal\Tests\package_manager\Kernel\TestStage;
 
 /**
  * @covers \Drupal\automatic_updates\Validator\StagedDatabaseUpdateValidator
@@ -31,10 +32,10 @@ class StagedDatabaseUpdateValidatorTest extends AutomaticUpdatesKernelTestBase {
   protected function setUp(): void {
     parent::setUp();
 
+    TestStage::$stagingRoot = $this->vfsRoot->url();
+
     /** @var \Drupal\Tests\automatic_updates\Kernel\TestCronUpdater $updater */
     $updater = $this->container->get('automatic_updates.cron_updater');
-    $updater->stagingRoot = $this->vfsRoot->url();
-
     $updater->begin(['drupal' => '9.8.2']);
     $updater->stage();