diff -r 8d42bf3b821d -r e1a8753eaad7 src/Pure/Build/build_cluster.scala
--- a/src/Pure/Build/build_cluster.scala	Sun Jun 15 13:40:03 2025 +0200
+++ b/src/Pure/Build/build_cluster.scala	Sun Jun 15 15:19:03 2025 +0200
@@ -208,7 +208,7 @@
     }
 
     def start(): Process_Result = {
-      val build_cluster_ml_platform = build_cluster_isabelle.ml_platform
+      val build_cluster_ml_platform = build_cluster_isabelle.ml_settings.ml_platform
       if (build_cluster_ml_platform != build_context.ml_platform) {
         error("Bad ML_PLATFORM: found " + build_cluster_ml_platform +
           ", but expected " + build_context.ml_platform)