diff -r a34edc1057c0 -r 774b53f7dc3a server/querier.py
--- a/server/querier.py	Thu Oct 01 12:34:49 2015 +0200
+++ b/server/querier.py	Fri Oct 02 10:04:12 2015 +0200
@@ -646,7 +646,7 @@
                 # so compute description manually even if there is only
                 # one solution
                 basedescr = [None] * len(plan.selected)
-                todetermine = zip(range(len(plan.selected)), repeat(False))
+                todetermine = list(zip(range(len(plan.selected)), repeat(False)))
                 descr = _build_descr(cnx, results, basedescr, todetermine)
             # FIXME: get number of affected entities / relations on non
             # selection queries ?