src/Pure/Admin/other_isabelle.scala

   /* components */
 
   def init_components(
     component_repository: String = Components.default_component_repository,
     components_base: Path = Components.default_components_base,
-    catalogs: List[String] = Nil,
+    catalogs: List[String] = Components.default_catalogs,
     components: List[String] = Nil
   ): List[String] = {
     val dir = Components.admin(isabelle_home)
 
     ("ISABELLE_COMPONENT_REPOSITORY=" + Bash.string(component_repository)) ::