diff --git a/mercurial/unionrepo.py b/mercurial/unionrepo.py
--- a/mercurial/unionrepo.py
+++ b/mercurial/unionrepo.py
@@ -128,9 +128,10 @@
 
     def addrevision(self, text, transaction, link, p1=None, p2=None, d=None):
         raise NotImplementedError
-    def addgroup(self, deltas, transaction, addrevisioncb=None):
+    def addgroup(self, deltas, linkmapper, transaction, addrevisioncb=None,
+                 maybemissingparents=False):
         raise NotImplementedError
-    def strip(self, rev, minlink):
+    def strip(self, minlink, transaction):
         raise NotImplementedError
     def checksize(self):
         raise NotImplementedError