diff -r 2cd5f1fac788 -r c93d046d4300 mercurial/chgserver.py
--- a/mercurial/chgserver.py	Sat Nov 17 19:11:45 2018 +0900
+++ b/mercurial/chgserver.py	Mon Nov 12 21:10:51 2018 +0900
@@ -246,6 +246,10 @@
     rpath = options['repository']
     path, newlui = dispatch._getlocal(newui, rpath, wd=cwd)
 
+    extensions.populateui(newui)
+    if newui is not newlui:
+        extensions.populateui(newlui)
+
     return (newui, newlui)
 
 class channeledsystem(object):