diff -r b2df121ccfc1 -r d73a7e3c618c src/Pure/Tools/build.scala
--- a/src/Pure/Tools/build.scala	Fri Nov 05 20:42:06 2021 +0100
+++ b/src/Pure/Tools/build.scala	Fri Nov 05 22:43:29 2021 +0100
@@ -499,11 +499,11 @@
       if (presentation_sessions.nonEmpty) {
         val presentation_dir = presentation.dir(store)
         progress.echo("Presentation in " + presentation_dir.absolute)
-        Presentation.update_global_index(presentation_dir)
+        Presentation.update_root(presentation_dir)
 
         for ((chapter, infos) <- presentation_sessions.groupBy(_.chapter).iterator) {
           val entries = infos.map(info => (info.name, info.description))
-          Presentation.update_chapter_index(presentation_dir, chapter, entries)
+          Presentation.update_chapter(presentation_dir, chapter, entries)
         }
 
         val resources = Resources.empty