anchor.diff:    #scheduler_state{logger = Logger} = State,
     #trace_state{
        clock_map = EarlyClockMap,
  -     done = [#event{actor = EarlyActor} = EarlyEvent|Done],
  -     index = EarlyIndex,
  -     sleeping = Sleeping
  +     done = [#event{actor = EarlyActor} = EarlyEvent|_],
  +     index = EarlyIndex
       } = TraceState,
     EarlyClock = lookup_clock_value(EarlyActor, Clock),
     Action =
  
positive.code:       {update, S, C} -> {S, C}
      end,
    more_interleavings_for_event(Rest, Event, Later, NewClock, State, NewTrace).
  
  not_dep(Trace, Actor, Index, Event) ->
    not_dep(Trace, Actor, Index, Event, []).
  
negative.code:             ?trace(Logger, "   races with ~s~n",
                     [?pretty_s(EarlyIndex, EarlyEvent)]),
              NC = max_cv(lookup_clock(EarlyActor, EarlyClockMap), Clock),
              case
                update_trace(Event, TraceState, Later, NewOldTrace, State)
              of
                skip -> {update_clock, NC};
                UpdatedNewOldTrace ->
                  concuerror_logger:plan(Logger),
                  {update, UpdatedNewOldTrace, NC}
              end
          end
      end,
  