diff -r c2ab1a970e82 -r 48abb09d49ea src/Pure/System/scala.scala
--- a/src/Pure/System/scala.scala	Sat Feb 27 21:36:58 2021 +0100
+++ b/src/Pure/System/scala.scala	Sat Feb 27 22:17:56 2021 +0100
@@ -249,5 +249,6 @@
   Isabelle_System.Copy_Dir,
   Isabelle_System.Copy_File,
   Isabelle_System.Copy_File_Base,
+  Isabelle_System.Rm_Tree,
   Isabelle_System.Download,
   Isabelle_Tool.Isabelle_Tools)