anchor.diff:  -spec explain_error(term()) -> string().
   
   explain_error(first_interleaving_crashed) ->
  -  {
  -    io_lib:format(
  -      "The first interleaving of your test had errors. Check the output file."
  -      " You may then use -i to tell Concuerror to continue or use other options"
  -      " to filter out the reported errors, if you consider them acceptable"
  -      " behaviours.",
  -      []),
  -    warning};
  +  {msg(first_interleaving_crashed), warning};
   explain_error({replay_mismatch, I, Event, NewEvent, Depth}) ->
     [EString, NEString] =
       [concuerror_printer:pretty_s(E, Depth) || E <- [Event, NewEvent]],
  
positive.code:             IndexedLate ={Index, Event#event{location = []}},
              concuerror_logger:race(Logger, IndexedEarly, IndexedLate);
             true ->
              ?unique(
                 Logger, ?linfo,
                 "You can see pairs of racing instructions (in the report and"
                 " --graph) with '--show_races true'~n",
                 [])
          end,
          {Rest, NC, S}
      end,
  
negative.code: 
  %%==============================================================================
  
  msg(first_interleaving_crashed) ->
    "The first interleaving of your test had errors. Check the output file."
      " You may then use -i to tell Concuerror to continue or use other options"
      " to filter out the reported errors, if you consider them acceptable"
      " behaviours.";
  msg(signal) ->
    "An abnormal exit signal was sent to a process. This is probably the worst"
      " thing that can happen race-wise, as any other side-effecting"
      " operation races with the arrival of the signal. If the test produces"
      " too many interleavings consider refactoring your code.~n";
  msg(show_races) ->
    "You can see pairs of racing instructions (in the report and"
      " --graph) with '--show_races true'~n";
  msg(shutdown) ->
    "A process crashed with reason 'shutdown'. This may happen when a"
      " supervisor is terminating its children. You can use '--treat_as_normal"
  