anchor.diff:  prop_format() ->
       ?FORALL({FmtArgs, MaxLen}, {gen_fmt_args(), gen_max_len()},
               begin
  +                FudgeLen = 31, %% trunc_io does not correctly calc safe size of pid/port/numbers
                   {FmtStr, Args} = build_fmt_args(FmtArgs),
                   try
                       Str = lists:flatten(trunc_io:format(FmtStr, Args, MaxLen)),
                       ?WHENFAIL(begin
  -                                  io:format("FmtStr: ~p\n", [FmtStr]),
  -                                  io:format("Args:   ~p\n", [Args]),
  -                                  io:format("MaxLen: ~p\n", [MaxLen]),
  -                                  io:format("ActLen: ~p\n", [length(Str)]),
  -                                  io:format("Str:    ~p\n", [Str])
  +                                  io:format(user, "FmtStr:   ~p\n", [FmtStr]),
  +                                  io:format(user, "Args:     ~p\n", [Args]),
  +                                  io:format(user, "FudgeLen: ~p\n", [FudgeLen]),
  +                                  io:format(user, "MaxLen:   ~p\n", [MaxLen]),
  +                                  io:format(user, "ActLen:   ~p\n", [length(Str)]),
  +                                  io:format(user, "Str:      ~p\n", [Str])
                                 end,
                                 %% Make sure the result is a printable list
                                 %% and if the format string is less than the length, 
  
positive.code:                               conjunction([{printable, Str == "" orelse 
                                                         io_lib:printable_list(Str)},
                                             {length, length(FmtStr) > MaxLen orelse 
                                                      length(Str) =< MaxLen}]))
                  catch
                      _:Err ->
                          io:format(user, "\nException: ~p\n", [Err]),
                          io:format("FmtStr: ~p\n", [FmtStr]),
                          io:format("Args:   ~p\n", [Args]),
                          false
                  end
              end).
  
negative.code: %%====================================================================
  
  eqc_test_() ->
      {timeout, 300,
       {spawn, 
        [?_assertEqual(true, quickcheck(numtests(500, ?QC_OUT(prop_format()))))]
       }}.
  
  %%====================================================================
  %% Shell helpers 
  