diff -r d9a54c4c9da9 -r 3cc73d00553c src/Pure/Admin/build_zipperposition.scala
--- a/src/Pure/Admin/build_zipperposition.scala	Sat Nov 28 20:18:29 2020 +0100
+++ b/src/Pure/Admin/build_zipperposition.scala	Sat Nov 28 21:56:24 2020 +0100
@@ -90,7 +90,7 @@
 
   val isabelle_tool =
     Isabelle_Tool("build_zipperposition", "build prover component from OPAM repository",
-    args =>
+      Scala_Project.here, args =>
     {
       var target_dir = Path.current
       var version = default_version