If you follow these steps, it should work:
First turn on the translation system:
framework:
translator: { fallback: en }
Create a constraint, just like you:
use Symfony\Component\Validator\Constraints as Assert;
class Friend
{
public $name;
}
Create a translation file in the validator directory for constraint messages, usually in the Resources / translations / directory of the directory, just like you.
test: my message
. , , ( , dev).
$ php app/console cache:clear
.