diff -r 022bf71515c9 -r bc592059d04f mercurial/chgserver.py
--- a/mercurial/chgserver.py	Mon Feb 24 13:22:15 2020 -0500
+++ b/mercurial/chgserver.py	Mon Mar 23 21:06:54 2020 +0530
@@ -83,6 +83,7 @@
     b'eol',  # uses setconfig('eol', ...)
     b'extdiff',  # uisetup will register new commands
     b'extensions',
+    b'fastannotate',  # affects annotate command and adds fastannonate cmd
     b'schemes',  # extsetup will update global hg.schemes
 ]