diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
index 96e526fe5fb0c900cbd198728a8e5636e36092ab_bWVyY3VyaWFsL2xvY2FscmVwby5weQ==..376395868b7b96ba3549f833b2d7b3cba590325b_bWVyY3VyaWFsL2xvY2FscmVwby5weQ== 100644
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -3073,6 +3073,8 @@
 
         def unlock():
             if self.dirstate.pendingparentchange():
+                msg = b"wlock release in the middle of a changing parents"
+                self.ui.develwarn(msg)
                 self.dirstate.invalidate()
             else:
                 self.dirstate.write(None)