%Warning-UNUSEDSIGNAL: t/t_lint_once_bad.v:19:14: Signal is not driven, nor used: 'unus1'
                                                : ... In instance t.sub1
   19 |    reg [A:0] unus1;    reg [A:0] unus2;
      |              ^~~~~
                       ... For warning description see https://verilator.org/warn/UNUSEDSIGNAL?v=latest
                       ... Use "/* verilator lint_off UNUSEDSIGNAL */" and lint_on around source to disable this message.
%Warning-UNUSEDSIGNAL: t/t_lint_once_bad.v:19:34: Signal is not driven, nor used: 'unus2'
                                                : ... In instance t.sub1
   19 |    reg [A:0] unus1;    reg [A:0] unus2;
      |                                  ^~~~~
%Error: Exiting due to