diff -r 3d8b37b1d798 -r 8342cba8eae8 src/Pure/ML/ml_process.scala
--- a/src/Pure/ML/ml_process.scala	Wed Aug 17 14:42:20 2022 +0200
+++ b/src/Pure/ML/ml_process.scala	Wed Aug 17 15:18:17 2022 +0200
@@ -80,7 +80,7 @@
     // session base
     val (init_session_base, eval_init_session) =
       session_base match {
-        case None => (sessions_structure.bootstrap, Nil)
+        case None => (Sessions.bootstrap_base, Nil)
         case Some(base) => (base, List("Resources.init_session_env ()"))
       }
     val init_session = Isabelle_System.tmp_file("init_session")