anchor.diff:                              erlang:throw('unknown gen_component command')
                       end
               end;
  -        {'$gc_unknown_event'} -> loop(UState, T1GCState);
  -        {'$gc_exception'} ->     loop(UState, T1GCState);
           unknown_event ->
               %% drop T2State, as it contains the error message
               on_unknown_event(Msg, UState, T1GCState),
  
positive.code:                 true -> loop(UState, bp_step_done(Msg, T1GCState))
              end;
          NewUState ->
              case element(?BP_ACTIVE, T1GCState) andalso gc_bpstepped(T1GCState) of
                  false -> loop(NewUState, T1GCState);
                  true -> loop(NewUState, bp_step_done(Msg, T1GCState))
              end
      end.
  
  -spec on_traced_msg(comm:message(), user_state(), gc_state())
  
negative.code:     T1GCState = on_bp(Msg, UState, GCState),
      Module  = gc_mod(T1GCState),
      Handler = gc_hand(T1GCState),
      try Handler(Msg, UState) of
          kill ->
              log:log(info, "[ gen_component ] ~.0p killed (~.0p:~.0p/2):",
                      [self(), Module, Handler]),
  