diff -r 224af78021de -r 1ced08423d59 mercurial/extensions.py
--- a/mercurial/extensions.py	Wed Dec 09 18:21:16 2020 -0500
+++ b/mercurial/extensions.py	Tue Dec 08 10:51:05 2020 -0500
@@ -810,7 +810,7 @@
     exts = {}
     for name, path in pycompat.iteritems(paths):
         doc = _disabledhelp(path)
-        if doc:
+        if doc and name != b'__index__':
             exts[name] = doc.splitlines()[0]
 
     return exts