hum strange.. because i try again directly on demobundle and it works:

```php
 94      * @return \Symfony\Component\HttpFoundation\Response
 95      */
 96     public function latestContentAction( $pathString, $contentTypeIdentifier, $limit, array $excludeLocations = array() )
 97     {
 98         $test = $this->getLegacyKernel()->runCallback(
 99         function () 
100         {
101                 // Here you can reuse $settingName and $test variables inside the legacy context
102                 $ini = eZINI::instance( 'site.ini' );
103                 return $ini->variable( 'DatabaseSettings', 'DatabaseImplementation' );
104         });
105 var_dump($test);
````
Could you paste your controller to a gist ?