src/Pure/PIDE/document.ML

 
       fun force_exec NONE = ()
         | force_exec (SOME exec_id) = ignore (Lazy.force (the_exec state exec_id));
 
       val _ = List.app Future.cancel execution;
-      fun await_cancellation () = uninterruptible (fn _ => Future.join_results) execution;
+      fun await_cancellation () =
+        uninterruptible (fn _ => fn () => Future.join_results execution) ();
 
       val execution' = (* FIXME proper node deps *)
         node_names_of version |> map (fn name =>
           Future.fork_pri 1 (fn () =>
             (await_cancellation ();