anchor.diff:      // run ``task`` and record the updated dependency stack in ``st``.
       | task :: tasks, [] ->
         debug "Loading" task;
  +      progress_callback task;
         Options.restore_cmd_line_options false |> ignore;
         let timestamped_task = update_task_timestamps task in
         let push_kind = if Options.lax () then LaxCheck else FullCheck in
  
positive.code: The original value of the ``repl_deps_stack`` field in ``st`` is used to skip
  already completed tasks.
  
  This function is stateful: it uses ``push_repl`` and ``pop_repl``. **)
  let run_repl_ld_transactions (st: repl_state) (tasks: list<repl_task>) =
    let debug verb task =
      if Options.debug_any () then
        Util.print2 "%s %s" verb (string_of_repl_task task) in
  
negative.code:   | None -> Inr st
    | Some (deps, tasks, dep_graph) ->
      let st = {st with repl_env=FStar.TypeChecker.Env.set_dep_graph st.repl_env dep_graph} in
      match run_repl_ld_transactions st tasks write_repl_ld_task_progress with
      | Inr st -> write_progress None []; Inr st
      | Inl st -> write_progress None []; Inl (st, deps)
  
  let rephrase_dependency_error issue =
    { issue with issue_message =
  