--- a/tests/test-unamend.t	Tue Apr 27 14:59:45 2021 -0700
+++ b/tests/test-unamend.t	Thu Feb 11 15:11:10 2021 -0800
@@ -284,6 +284,7 @@
 
   $ hg --config experimental.evolution=createmarkers unamend
   abort: cannot unamend changeset with children
+  (see 'hg help evolution.instability')
   [10]
 
   $ hg unamend