--- a/mercurial/revlog.py	Sat Nov 02 14:45:57 2019 +0100
+++ b/mercurial/revlog.py	Sat Nov 02 15:21:28 2019 +0100
@@ -630,7 +630,7 @@
             # populate mapping down to the initial node
             node0 = self.index[0][7]  # get around changelog filtering
             self.rev(node0)
-        return self._nodecache
+        return self.index.nodemap
 
     def hasnode(self, node):
         try: