diff -r 4ca5932065ca -r 96b2e66dfa74 mercurial/debugcommands.py
--- a/mercurial/debugcommands.py	Thu Aug 02 21:07:30 2018 +0900
+++ b/mercurial/debugcommands.py	Mon Jun 11 12:32:16 2018 +0900
@@ -949,8 +949,7 @@
         ui.write("%s\n" % f)
 
 @command('debugformat',
-         [] + cmdutil.formatteropts,
-        _(''))
+         [] + cmdutil.formatteropts)
 def debugformat(ui, repo, **opts):
     """display format information about the current repository