diff -r a476ee0b8e79 -r 0c7b018d3258 mercurial/dirstate.py
--- a/mercurial/dirstate.py	Sun Sep 07 11:33:22 2014 -0700
+++ b/mercurial/dirstate.py	Wed Sep 17 13:08:03 2014 -0700
@@ -257,8 +257,8 @@
         See localrepo.setparents()
         """
         if self._parentwriters == 0:
-            raise ValueError("cannot set dirstate parent without " +
-                " calling dirstate.begingparentchange")
+            raise ValueError("cannot set dirstate parent without "
+                             "calling dirstate.beginparentchange")
 
         self._dirty = self._dirtypl = True
         oldp2 = self._pl[1]