--- a/tests/test-basic.t	Sun Jan 07 12:09:33 2018 +0900
+++ b/tests/test-basic.t	Mon Jan 08 11:11:06 2018 +0900
@@ -87,6 +87,13 @@
   checking files
   1 files, 1 changesets, 1 total revisions
 
+Repository root:
+
+  $ hg root
+  $TESTTMP/t
+  $ hg log -l1 -T '{reporoot}\n'
+  $TESTTMP/t
+
 At the end...
 
   $ cd ..