diff -r db87432df8de -r b8cb1bdbc8d7 tests/test-topic-stack.t
--- a/tests/test-topic-stack.t	Wed Dec 12 01:19:30 2018 +0800
+++ b/tests/test-topic-stack.t	Thu Dec 13 17:26:26 2018 +0100
@@ -366,11 +366,11 @@
   5 default {foo} draft c_f
 
   $ hg log -r 'stack(foo)'
-  hg: parse error: stack() takes no argument, it works on current topic
+  hg: parse error: stack takes no arguments, it works on current topic
   [255]
 
   $ hg log -r 'stack(foobar)'
-  hg: parse error: stack() takes no argument, it works on current topic
+  hg: parse error: stack takes no arguments, it works on current topic
   [255]
 
 Case with multiple heads on the topic