symfony
diff --git a/‎src/Symfony/Component/Cache/Traits/RedisTrait.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/Cache/Traits/RedisTrait.php
+4Lines changed: 4 additions & 0 deletions b/‎src/Symfony/Component/Cache/Traits/RedisTrait.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/Cache/Traits/RedisTrait.php
+4Lines changed: 4 additions & 0 deletions
@@ -16,6 +16,7 @@
 use Predis\Connection\Aggregate\PredisCluster;
 use Predis\Connection\Aggregate\RedisCluster;
 use Predis\Response\Status;
+use Symfony\Component\Cache\Exception\CacheException;
 use Symfony\Component\Cache\Exception\InvalidArgumentException;
 
 /**
@@ -108,6 +109,9 @@ public static function createConnection($dsn, array $options = array())
             $params += $query;
         }
         $params += $options + self::$defaultConnectionOptions;
+        if (null === $params['class'] && !extension_loaded('redis') && !class_exists(\Predis\Client::class)) {
+            throw new CacheException(sprintf('Cannot find the "redis" extension, and "predis/predis" is not installed: %s', $dsn));
+        }
         $class = null === $params['class'] ? (extension_loaded('redis') ? \Redis::class : \Predis\Client::class) : $params['class'];
 
         if (is_a($class, \Redis::class, true)) {