diff -r 58e7ee23ddbd -r b7b8a1538161 mercurial/debugcommands.py
--- a/mercurial/debugcommands.py	Mon Jun 22 22:47:43 2020 -0700
+++ b/mercurial/debugcommands.py	Tue Nov 03 20:18:26 2020 -0800
@@ -3376,6 +3376,7 @@
 
     s = wireprotoserver.sshserver(ui, repo, logfh=logfh)
     s.serve_forever()
+    sys.exit(0)
 
 
 @command(b'debugsetparents', [], _(b'REV1 [REV2]'))