--- a/tests/test-topic-tutorial.t	Sat Oct 05 14:31:19 2019 -0400
+++ b/tests/test-topic-tutorial.t	Thu Oct 10 08:22:41 2019 +0700
@@ -477,7 +477,7 @@
 
   $ hg merge
   abort: branch 'default' has one head - please merge with an explicit rev
-  (run 'hg heads' to see all heads)
+  (run 'hg heads' to see all heads, specify rev with -r)
   [255]
 
 But the topic will see that branch head as a valid destination: