diff -r 5cb72229f0e9 -r 1b183edbb68e tests/simplestorerepo.py
--- a/tests/simplestorerepo.py	Fri Oct 19 13:44:25 2018 +0200
+++ b/tests/simplestorerepo.py	Wed Sep 26 14:41:15 2018 -0700
@@ -459,7 +459,12 @@
         self._refreshindex()
         self._svfs.write(self._indexpath, cbor.dumps(self._indexdata))
 
-    def addgroup(self, deltas, linkmapper, transaction, addrevisioncb=None):
+    def addgroup(self, deltas, linkmapper, transaction, addrevisioncb=None,
+                 maybemissingparents=False):
+        if maybemissingparents:
+            raise error.Abort(_('simple store does not support missing parents '
+                                'write mode'))
+
         nodes = []
 
         transaction.addbackup(self._indexpath)