%Warning-COVERIGN: t/t_covergroup_member_event_unsup.v:13:5: Unsupported: 'covergroup' clocking event on member variable
                                                           : ... note: In instance 't'
   13 |     covergroup cov1 @m_z;
      |     ^~~~~~~~~~
                   ... 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