anchor.diff:        case NextExploring =< State#scheduler_state.interleaving_bound of
           true -> NextState;
           false ->
  -          Bound = "Reached interleaving bound (~p)~n",
  -          ?unique(Logger, ?lwarning, Bound, [N]),
  +          UniqueMsg = "Reached interleaving bound (~p)~n",
  +          ?unique(Logger, ?lwarning, UniqueMsg, [N]),
             NextState#scheduler_state{trace = []}
         end
     end.
   
  -filter_warnings(Warnings, []) -> Warnings;
  -filter_warnings(Warnings, [Ignore|Rest] = Ignored) ->
  +filter_warnings(Warnings, [], _) -> Warnings;
  +filter_warnings(Warnings, [Ignore|Rest] = Ignored, Logger) ->
     case lists:keytake(Ignore, 1, Warnings) of
  -    false -> filter_warnings(Warnings, Rest);
  -    {value, _, NewWarnings} -> filter_warnings(NewWarnings, Ignored)
  +    false -> filter_warnings(Warnings, Rest, Logger);
  +    {value, _, NewWarnings} ->
  +      UniqueMsg = "Some errors were ignored ('--ignore_error').~n",
  +      ?unique(Logger, ?lwarning, UniqueMsg, []),
  +      filter_warnings(NewWarnings, Ignored, Logger)
     end.
   
   %%------------------------------------------------------------------------------
  
positive.code:      exploring = N,
       ignore_error = Ignored,
       logger = Logger} = State,
    Warnings = filter_warnings(UnfilteredWarnings, Ignored),
    case UnfilteredWarnings =/= Warnings of
      true ->
        Message = "Some errors were ignored ('--ignore_error').~n",
        ?unique(Logger, ?lwarning, Message, []);
      false ->
        ok
    end,
    Log =
      case Warnings =:= [] of
        true -> none;
  
negative.code:   #scheduler_state{
       current_warnings = Warnings,
       depth_bound = Bound,
       logger = Logger,
       trace = [#trace_state{index = I}|Old]} = State) when I =:= Bound + 1 ->
    UniqueMsg =
      "Some interleaving reached the depth bound (~p). Consider limiting the size"
      " of the test or increasing the bound.~n",
    ?unique(Logger, ?lwarning, UniqueMsg, [Bound]),
    NewState =
      State#scheduler_state{
        current_warnings = [{depth_bound, Bound}|Warnings],
  