diff -r 4ae3ba9e4d7a -r b6081c2c4647 mercurial/discovery.py
--- a/mercurial/discovery.py	Sat May 12 00:19:30 2012 +0200
+++ b/mercurial/discovery.py	Sat May 12 00:24:07 2012 +0200
@@ -105,7 +105,7 @@
     og.commonheads, _any, _hds = commoninc
 
     # compute outgoing
-    if not repo._phaseroots[phases.secret]:
+    if not repo._phasecache.phaseroots[phases.secret]:
         og.missingheads = onlyheads or repo.heads()
     elif onlyheads is None:
         # use visible heads as it should be cached