%Error: t/t_past_bad.v:11: $past tick value must be constant (IEEE 2017 16.9.3)
      if ($past(d, 0)) $stop;   
          ^~~~~
%Warning-TICKCOUNT: t/t_past_bad.v:12: $past tick value of 10000 may have a large performance cost
      if ($past(d, 10000)) $stop;   
                   ^~~~~
                    ... Use "/* verilator lint_off TICKCOUNT */" and lint_on around source to disable this message.
%Error: Exiting due to