--- a/mercurial/localrepo.py	Sat Nov 17 19:11:45 2018 +0900
+++ b/mercurial/localrepo.py	Mon Nov 12 21:10:51 2018 +0900
@@ -454,6 +454,7 @@
     if loadhgrc(ui, wdirvfs, hgvfs, requirements):
         afterhgrcload(ui, wdirvfs, hgvfs, requirements)
         extensions.loadall(ui)
+        extensions.populateui(ui)
 
     # Set of module names of extensions loaded for this repository.
     extensionmodulenames = {m.__name__ for n, m in extensions.extensions(ui)}