Comment 1 for bug 1210590

I could bypass this problem with this code at keystone/assignment/core.py:

    def _roles_from_role_dicts(self, dict_list, inherited):
        role_list = []
        for d in dict_list:
            # To bypass the problem
            if isinstance(d, unicode):
                d = {'id':d}
            #
            if ((not d.get('inherited_to') and not inherited) or
               (d.get('inherited_to') == 'projects' and inherited)):
                role_list.append(d['id'])
        return role_list