diff -r a77e61b45384 -r 2cfdf5241096 mercurial/smartset.py
--- a/mercurial/smartset.py	Tue Apr 25 01:52:30 2017 +0530
+++ b/mercurial/smartset.py	Fri Apr 28 01:13:07 2017 +0530
@@ -245,7 +245,7 @@
     @util.propertycache
     def _list(self):
         # _list is only lazily constructed if we have _set
-        assert '_set' in self.__dict__
+        assert r'_set' in self.__dict__
         return list(self._set)
 
     def __iter__(self):