diff -r d69d86e7d6c8 -r 7be610198360 mercurial/commands.py
--- a/mercurial/commands.py	Sun Oct 09 13:59:20 2016 +0200
+++ b/mercurial/commands.py	Sun Oct 09 09:42:46 2016 -0400
@@ -2787,7 +2787,7 @@
     if not problems:
         fm.data(problems=problems)
     fm.condwrite(problems, 'problems',
-                 _("%s problems detected,"
+                 _("%d problems detected,"
                    " please check your install!\n"), problems)
     fm.end()