diff -r b4537125eb3c -r c36a3fcfc36b mercurial/upgrade.py
--- a/mercurial/upgrade.py	Mon Apr 13 18:04:55 2020 +0200
+++ b/mercurial/upgrade.py	Wed Apr 15 18:10:19 2020 +0200
@@ -628,14 +628,12 @@
     """
     newactions = []
 
-    knownreqs = supporteddestrequirements(repo)
-
     for d in deficiencies:
-        name = d.name
+        name = d._requirement
 
         # If the action is a requirement that doesn't show up in the
         # destination requirements, prune the action.
-        if name in knownreqs and name not in destreqs:
+        if name is not None and name not in destreqs:
             continue
 
         newactions.append(d)