diff -r baffdfa5bd1a -r 02b17231f6c3 mercurial/configitems.py
--- a/mercurial/configitems.py	Thu Jul 02 19:59:59 2020 +0200
+++ b/mercurial/configitems.py	Tue Jun 09 11:22:31 2020 +0200
@@ -1231,6 +1231,10 @@
     b'ui', b'askusername', default=False,
 )
 coreconfigitem(
+    b'ui', b'available-memory', default=None,
+)
+
+coreconfigitem(
     b'ui', b'clonebundlefallback', default=False,
 )
 coreconfigitem(