src/Tools/VSCode/src/vscode_resources.scala

 
   /* resolve dependencies */
 
   val thy_info = new Thy_Info(this)
 
-  def resolve_dependencies(session: Session): Boolean =
+  def resolve_dependencies(session: Session, watcher: File_Watcher): Boolean =
   {
     state.change_result(st =>
       {
         val thys =
           (for ((_, model) <- st.models.iterator if model.is_theory)

         val loaded_models =
           (for {
             dep <- thy_info.dependencies("", thys).deps.iterator
             file = node_file(dep.name)
             if !st.models.isDefinedAt(file)
+            _ = watcher.register_parent(file)
             text <- try_read(file)
           }
           yield {
             val model = Document_Model.init(session, node_name(file))
             val model1 = (model.update_text(text) getOrElse model).external(true)