[devtools/testlib] avoid hidding AttributeError in create_user() commit() might raise a AttributeError too. Use getattr(req, 'cnx', req) instead, which is a form already used to get the real cnx in some code: cubicweb/rset.py:577: cnx = getattr(self.req, 'cnx', self.req) cubicweb/schema.py:353: with getattr(_cw, 'cnx', _cw).security_enabled(read=False): We could use if hasattr(req, 'commit') here too but it lead to 3 additionals lines. Maybe we should have commit() and rollback() on cubicweb.web.request.ConnectionCubicWebRequestBase too ?

Fix DeprecationWarning: invalid escape sequence \

DeprecationWarning: The 'warn' method is deprecated, use 'warning' instead