%Warning-COVERIGN: t/t_cover_fsm_concat_unsup.v:12:17: Ignoring unsupported: FSM coverage with CONCAT
   12 |   assign c = ({a, b} == 8'h00);
      |                 ^
                   ... For warning description see https://verilator.org/warn/COVERIGN?v=latest
                   ... Use "/* verilator lint_off COVERIGN */" and lint_on around source to disable this message.
%Error: Exiting due to