--- a/mercurial/namespaces.py	Sun Feb 25 18:56:06 2018 +0900
+++ b/mercurial/namespaces.py	Sun Feb 25 18:52:51 2018 +0900
@@ -89,9 +89,9 @@
         # we only generate a template keyword if one does not already exist
         if namespace.name not in templatekw.keywords:
             templatekeyword = registrar.templatekeyword(templatekw.keywords)
-            @templatekeyword(namespace.name)
-            def generatekw(**args):
-                return templatekw.shownames(namespace.name, **args)
+            @templatekeyword(namespace.name, requires={'repo', 'ctx', 'templ'})
+            def generatekw(context, mapping):
+                return templatekw.shownames(context, mapping, namespace.name)
 
     def singlenode(self, repo, name):
         """