src/Pure/System/components.scala

--- a/src/Pure/System/components.scala	Tue Jan 24 20:39:11 2023 +0100
+++ b/src/Pure/System/components.scala	Tue Jan 24 20:43:55 2023 +0100
@@ -39,6 +39,7 @@
     Isabelle_System.getenv("ISABELLE_COMPONENT_REPOSITORY")
 
   val default_components_base: Path = Path.explode("$ISABELLE_COMPONENTS_BASE")
+  val standard_components_base: Path = Path.explode("$USER_HOME/.isabelle/contrib")
 
   val default_catalogs: List[String] = List("main")
   val optional_catalogs: List[String] = List("main", "optional")