Fatal error: Uncaught Error: Class "Symfony\Component\DependencyInjection\Dumper\Dumper" not found in /media/jean/learning/huagai/drupal/vendor/symfony/dependency-injection/Dumper/XmlDumper.php:34 Stack trace: #0 {main} thrown in /media/jean/learning/huagai/drupal/vendor/symfony/dependency-injection/Dumper/XmlDumper.php on line 34