src/Pure/System/isabelle_system.scala

--- a/src/Pure/System/isabelle_system.scala	Sat Jun 26 20:55:43 2021 +0200
+++ b/src/Pure/System/isabelle_system.scala	Mon Jun 28 12:29:00 2021 +0200
@@ -108,7 +108,7 @@
             default(sys.env + ("ISABELLE_JDK_HOME" -> File.standard_path(jdk_home())),
               "TEMP_WINDOWS" -> temp_windows),
             "HOME" -> user_home),
-          "ISABELLE_APP" -> "true")
+          "ISABELLE_APP" -> isabelle_app)
       }
 
       val settings =