Cannot reference Alice fixture in EntityContext following step (KnpLabs/FriendlyContexts) - Behat

Question

I use the really cool knplabs/friendlycontexts bundle to test VictoireDCMS, a Symfony2 open source DCMS.

Actually, this is working pretty well in spite of the kind of my project (not a basic symfony-project architecture but a suite of bundles with a functionnal test application).

But... I'm now blocked to use alice reference in the EntityContext. The documentation give these examples :

user.yml

App\Entity\User:
    user-john:
        firstname: John
        lastname: Doe
    user-admin:
        firstname: Admin
        lastname: Admin

my.feature

@alice(User)
Feature: My feature
    The feature description

    Background:
        Given the following products
            | name  | user  |
            | Ball  | John  |
            | Shoes | Admin |

    ...

This is really looking good and is exactly what I want to do and here is my code:

template.yml (full file)

Victoire\Bundle\TemplateBundle\Entity\Template:
    template_base:
        name: Base
        ...

my.feature (full file)

Given the following page:
    | name      | slug     | locale | template |
    | tatooine  | tatooine | fr     | base     |

Unfortunatelly, it doesn't work properly and I have this error when I run my feature :

Expected value of type "Victoire\Bundle\TemplateBundle\Entity\Template" for association field "Victoire\Bundle\PageBundle\Entity\BasePage#$template", got "string" instead. (Doctrine\ORM\ORMInvalidArgumentException)

I can't figure this out and can't see any difference btw the example and my code... Any help would be appreciated.