Hello, while updating a 3.3.13 project to 3.3.14, I've an issue with the following routing declaration:

my_route:
    resource: 'Foo\BarBundle\Controller\UserController'
    type: annotation
    prefix: /

The error is :

FileLocatorFileNotFoundException
The file "Foo\BarBundle\Controller\UserController" does not exist (in: /srv/app/app/config, /srv/app/app, /srv/app/app/Resources) in Foo\BarBundle\Controller\UserController (which is being imported from "/srv/app/app/config/routing.yml"). Make sure annotations are enabled.

The problem :
The AnnotatedRouteControllerLoader is called after the AnnotationDirectoryLoader one, and both can support the (string, 'annotation') routing entry.

It seems it's caused by the merge of #25113 in the 3.3 branch. This problem can be fixed by sensiolabs/SensioFrameworkExtraBundle#537 , but the commit is only available for the 5.1.3 SensioFrameworkExtraBundle version, whereas the 3.3 symfony branch only requires "sensio/framework-extra-bundle": "^3.0.2".

Another PR, the #25231 one, can fix the problem but has been rejected in favor of the SensioFrameworkExtraBundle one.