[CWEP002 migration] properly raise exception on (add|drop)_relation_definition for computed relation
Related to #3546717
# -*- coding: utf-8 -*-
# copyright %(year)s %(author)s, all rights reserved.
# contact %(author-web-site)s -- mailto:%(author-email)s
#
%(long-license)s
"""%(distname)s repository side views, usually for notification"""