diff -r cf08aaaea7f0 -r ac96ff471c9a mercurial/configitems.py
--- a/mercurial/configitems.py	Fri Sep 15 19:21:08 2017 +0200
+++ b/mercurial/configitems.py	Fri Jun 30 03:45:31 2017 +0200
@@ -582,6 +582,9 @@
 coreconfigitem('verify', 'skipflags',
     default=None,
 )
+coreconfigitem('web', 'accesslog',
+    default='-',
+)
 coreconfigitem('worker', 'backgroundclose',
     default=dynamicdefault,
 )