mercurial/configitems.py

--- a/mercurial/configitems.py	Sun Sep 06 10:33:12 2020 +0200
+++ b/mercurial/configitems.py	Thu Sep 17 22:34:36 2020 -0700
@@ -635,9 +635,6 @@
 coreconfigitem(
     b'experimental', b'httppostargs', default=False,
 )
-coreconfigitem(
-    b'experimental', b'mergedriver', default=None,
-)
 coreconfigitem(b'experimental', b'nointerrupt', default=False)
 coreconfigitem(b'experimental', b'nointerrupt-interactiveonly', default=True)