set path for cache dir by environment variable also

composer.json

@@ -6,6 +6,10 @@
         {
             "name": "Sebastian Kehr",
             "email": "kehr@ub.uni-leipzig.de"
+        },
+        {
+            "name": "Robert Lange",
+            "email": "lange@ub.uni-leipzig.de"
         }
     ],
     "autoload": {

src/Cache/AbstractFilesystemCacheFactory.php

@@ -33,9 +33,12 @@ abstract class AbstractFilesystemCacheFactory
         $name = $this->getName();
         $config = $container->get('config')['symfony_serializer'] ?? [];
         $cacheConfig = $config['caches'][$name] ?? [];
-
-        $directory = $cacheConfig['directory'] ?? $config['cache_directory'] ??
-            getcwd() . '/data/cache/symfony-serializer';
+    
+        if (getenv('SERIALIZER_BRIDGE_CACHE_DIR')) {
+            $directory = getenv('SERIALIZER_BRIDGE_CACHE_DIR');
+        } else {
+            $directory = $cacheConfig['directory'] ?? $config['cache_directory'] ?? '/var/cache';
+        }
 
         $lifetime = $cacheConfig['lifetime'] ?? $config['cache_lifetime'] ?? 0;
         $namespace = $cacheConfig['namespace'] ?? md5($name);