diff -r 392d6d599286 -r 1d3a9bb46339 cubicweb/devtools/repotest.py
--- a/cubicweb/devtools/repotest.py	Thu Mar 30 10:43:49 2017 +0200
+++ b/cubicweb/devtools/repotest.py	Thu Mar 30 11:56:09 2017 +0200
@@ -251,7 +251,7 @@
         # use cnx.user.eid to get correct owned_by relation, unless explicit eid
         with self.admin_access.cnx() as cnx:
             user_eid = cnx.user.eid
-            cnx.user._cw.data[user_session_cache_key(user_eid, 'groups')] = set(groups)
+            cnx.user._cw.transaction_data[user_session_cache_key(user_eid, 'groups')] = set(groups)
             yield cnx
 
     def qexecute(self, rql, args=None, build_descr=True):