diff -r 006ff7268c5c -r 55e8efa2451a mercurial/context.py
--- a/mercurial/context.py	Wed Feb 07 23:22:53 2018 +0900
+++ b/mercurial/context.py	Tue Feb 06 22:36:38 2018 +0900
@@ -46,6 +46,7 @@
     scmutil,
     sparse,
     subrepo,
+    subrepoutil,
     util,
 )
 
@@ -173,7 +174,7 @@
 
     @propertycache
     def substate(self):
-        return subrepo.state(self, self._repo.ui)
+        return subrepoutil.state(self, self._repo.ui)
 
     def subrev(self, subpath):
         return self.substate[subpath][1]