Throw an exception when the serializer component is not loaded

src/Symfony/Component/Messenger/Transport/Serialization/Serializer.php

@@ -13,6 +13,7 @@ namespace Symfony\Component\Messenger\Transport\Serialization;
 
 use Symfony\Component\Messenger\Envelope;
 use Symfony\Component\Messenger\Exception\InvalidArgumentException;
+use Symfony\Component\Messenger\Exception\RuntimeException;
 use Symfony\Component\Serializer\Encoder\JsonEncoder;
 use Symfony\Component\Serializer\Encoder\XmlEncoder;
 use Symfony\Component\Serializer\Normalizer\ObjectNormalizer;
@@ -37,6 +38,10 @@ class Serializer implements SerializerInterface
 
     public static function create(): self
     {
+        if (!class_exists(SymfonySerializer::class)) {
+            throw new RuntimeException(sprintf('The default Messenger Serializer requires Symfony\'s Serializer component. Try running "composer require symfony/serializer".'));
+        }
+
         $encoders = array(new XmlEncoder(), new JsonEncoder());
         $normalizers = array(new ObjectNormalizer());
         $serializer = new SymfonySerializer($normalizers, $encoders);