Fatal error: Uncaught Error: Interface "Drupal\Component\Plugin\Derivative\DeriverInterface" not found in /home/www/drupal8/test/core/tests/Drupal/Tests/Core/Plugin/Discovery/TestDerivativeDiscovery.php:10 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/tests/Drupal/Tests/Core/Plugin/Discovery/TestDerivativeDiscovery.php on line 10