anchor.diff:    ?debug_flag(?short_builtin, {'built-in', Module, Name, Arity, Location}),
     %% {Stack, ResetInfo} = reset_stack(Info),
     %% ?debug_flag(?stack, {stack, Stack}),
  -  LocatedInfo = locate_next_event(Location, Info),%ResetInfo),
  +  LocatedInfo = add_location_info(Location, Info),%ResetInfo),
     try
  +    %% XXX: TODO If replaying, inspect if original crashed and replay crash
       {Value, #concuerror_info{next_event = Event} = UpdatedInfo} =
         run_built_in(Module, Name, Arity, Args, LocatedInfo),
       ?debug_flag(?builtin, {'built-in', Module, Name, Arity, Value, Location}),
  
positive.code:          next_event = NextEvent,
           trap_exit = Trapping
          } = UpdatedInfo =
          locate_next_event(Location, ReceiveInfo),
        ReceiveEvent =
          #receive_event{
             message = MessageOrAfter,
  
negative.code:       {true, Info#concuerror_info{next_event = NewEvent}}
    end;
  
  run_built_in(erlang, link, 1, [Pid], Info) ->
    #concuerror_info{links = Old, processes = Processes} = Info,
    case ets:lookup(Processes, Pid) =/= [] of
      false ->
        ?debug_flag(?undefined, {link_to_external, Pid}),
        throw({error, badarg});
      true ->
        Pid ! {link, self(), confirm},
        receive
          success ->
            NewInfo = Info#concuerror_info{links = ordsets:add_element(Pid, Old)},
            {true, NewInfo};
          failed ->
            throw({error, badarg})
  