--- a/mercurial/obsolete.py	Mon May 18 16:56:04 2015 -0500
+++ b/mercurial/obsolete.py	Mon May 18 23:43:36 2015 -0500
@@ -299,7 +299,7 @@
 
     # Loop on markers
     stop = len(data) - _fm1fsize
-    ufixed = util.unpacker(_fm1fixed)
+    ufixed = struct.Struct(_fm1fixed).unpack
 
     while off <= stop:
         # read fixed part