--- a/mercurial/keepalive.py	Thu Oct 25 21:33:43 2018 +0800
+++ b/mercurial/keepalive.py	Mon Oct 29 16:23:42 2018 -0400
@@ -442,7 +442,10 @@
         data = self._raw_read(amt)
 
         self.receivedbytescount += len(data)
-        self._connection.receivedbytescount += len(data)
+        try:
+            self._connection.receivedbytescount += len(data)
+        except AttributeError:
+            pass
         try:
             self._handler.parent.receivedbytescount += len(data)
         except AttributeError: