--- a/mercurial/localrepo.py	Sun May 17 18:33:45 2020 -0400
+++ b/mercurial/localrepo.py	Tue May 26 08:07:24 2020 -0700
@@ -1456,6 +1456,8 @@
 
     @storecache(b'00changelog.i')
     def changelog(self):
+        # load dirstate before changelog to avoid race see issue6303
+        self.dirstate.prefetch_parents()
         return self.store.changelog(txnutil.mayhavepending(self.root))
 
     @storecache(b'00manifest.i')