diff -r d761ef24d6e1 -r e6fd7930cf0b mercurial/localrepo.py
--- a/mercurial/localrepo.py	Mon Mar 27 18:08:05 2017 +0200
+++ b/mercurial/localrepo.py	Mon Mar 27 16:00:47 2017 +0200
@@ -650,6 +650,7 @@
         return hook.hook(self.ui, self, name, throw, **args)
 
     def tag(self, names, node, message, local, user, date, editor=False):
+        self.ui.deprecwarn("use 'tagsmod.tag' instead of 'repo.tag'", '4.2')
         tagsmod.tag(self, names, node, message, local, user, date,
                     editor=editor)