--- a/mercurial/revlogutils/debug.py	Mon Sep 16 15:36:44 2024 +0200
+++ b/mercurial/revlogutils/debug.py	Thu Sep 12 16:27:58 2024 -0400
@@ -6,6 +6,8 @@
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
+from __future__ import annotations
+
 import collections
 import string