--- a/tests/test-merge-tools.t	Mon Jul 23 22:51:50 2018 -0700
+++ b/tests/test-merge-tools.t	Mon Jul 23 22:51:53 2018 -0700
@@ -1748,7 +1748,9 @@
   missingbinary.executable=doesnotexist
   # hg update -C 1
   $ hg merge -y -r 2 --config ui.merge=missingbinary
+  couldn't find merge tool missingbinary (for pattern f)
   merging f
+  couldn't find merge tool missingbinary (for pattern f)
   revision 1
   space
   revision 0