Use cachedir as the logdir for build purposes

see symfony/symfony#45579

config/packages/monolog.yaml

@@ -11,7 +11,7 @@ monolog:
       ident: openconext-profile
       type: stream
       path: "php://stderr"
-      formatter: \OpenConext\Infrastructure\Monolog\Formatter\JsonFormatter
+      formatter: 'OpenConext\Infrastructure\Monolog\Formatter\JsonFormatter'
     console:
       path: "php://stderr"
       type: console

src/OpenConext/Kernel.php

@@ -31,4 +31,15 @@ public function getProjectDir(): string
     {
         return dirname(__DIR__, 2);
     }
+
+    /**
+     * Although we don't use the log dir, the method is required
+     * to be implemented because it is required during building of the container
+     */
+    public function getLogDir(): string
+    {
+        return $this->getCacheDir();
+    }
+
+
 }