--- a/mercurial/configitems.py	Wed Jan 15 15:47:59 2020 +0100
+++ b/mercurial/configitems.py	Wed Jan 15 15:48:09 2020 +0100
@@ -406,6 +406,9 @@
     b'devel', b'legacy.exchange', default=list,
 )
 coreconfigitem(
+    b'devel', b'persistent-nodemap', default=False,
+)
+coreconfigitem(
     b'devel', b'servercafile', default=b'',
 )
 coreconfigitem(