tuned;

--- a/src/Pure/Thy/presentation.scala	Wed Aug 17 15:18:17 2022 +0200
+++ b/src/Pure/Thy/presentation.scala	Wed Aug 17 15:30:42 2022 +0200
@@ -134,7 +134,7 @@
       val batches =
         presentation_sessions.foldLeft((Set.empty[String], List.empty[Batch]))(
           { case ((seen, batches), session) =>
-              val thys = deps(session).loaded_theories.keys.filterNot(seen)
+              val thys = deps(session).loaded_theories.keys_iterator.filterNot(seen).toList
               (seen ++ thys, (session, thys) :: batches)
           })._2