hi,

the constructor of Symfony\Component\Security\Acl\Domain\RoleSecurityIdentity\RoleSecurityIdentity takes $role as a parameter and checks if it is an instance of Symfony\Component\Security\Core\Role\Role. Following the guidelines in http://symfony.com/doc/master/cookbook/security/entity_provider.html, our Role class implements RoleInterface. This results in RoleSecurityIdentity::role being populated with an object during the PermissionsEvaluation phase.

the fix, for me was easy, and should not break any other parts of the implementation, as Core\Role\Role also implements Core\Role\RoleInterface.

[[WARNING: HANDWRITTEN DIFF]]
<<<
[Symfony\Component\Security\Acl\Domain\RoleSecurityIdentity\RoleSecurityIdentity.php]
-- use Symfony\Component\Security\Core\Role\Role;
++ use Symfony\Component\Security\Core\Role\RoleInterface;
[...]
public function __construct($role)
{
-- if ($role instanceof Role) {
++ if ($role instanceof RoleInterface) {

i can submit a proper patch if required.

regards,
sb