--- a/hgext/obsolete.py	Tue Jul 31 12:45:45 2012 +0200
+++ b/hgext/obsolete.py	Tue Jul 31 15:04:59 2012 +0200
@@ -1009,10 +1009,18 @@
     if util.safehasattr(repo, '_journalfiles'): # Hg 2.2
         o_journalfiles = repo._journalfiles
     o_writejournal = repo._writejournal
+    o_hook = repo.hook
 
 
     class obsoletingrepo(repo.__class__):
 
+        # workaround
+        def hook(self, name, throw=False, **args):
+            if 'pushkey' in name:
+                args.pop('new')
+                args.pop('old')
+            return o_hook(name, throw=False, **args)
+
         ### Public method
         def obsoletedby(self, node):
             """return the set of node that make <node> obsolete (obj)"""