%Warning-NONSTD: t/t_covergroup_cross_opt_unsup.v:19:34: Non-standard hierarchical reference as a coverage cross item (an implicit coverpoint)
   19 |     cross_hier: cross cp_a, s_cfg.m_p;
      |                                  ^
                 ... For warning description see https://verilator.org/warn/NONSTD?v=latest
                 ... Use "/* verilator lint_off NONSTD */" and lint_on around source to disable this message.
%Warning-COVERIGN: t/t_covergroup_cross_opt_unsup.v:13:7: Ignoring unsupported coverage cross option: 'per_instance'
   13 |       option.per_instance = 1;   
      |       ^~~~~~
                   ... 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.
%Warning-COVERIGN: t/t_covergroup_cross_opt_unsup.v:15:33: Unsupported: cross of 'var_x' which is not a coverpoint (implicit coverpoint)
                                                         : ... note: In instance 't'
   15 |     cross_implicit: cross cp_a, var_x;
      |                                 ^~~~~
%Warning-COVERIGN: t/t_covergroup_cross_opt_unsup.v:19:34: Unsupported: cross of hierarchical reference (implicit coverpoint)
                                                         : ... note: In instance 't'
   19 |     cross_hier: cross cp_a, s_cfg.m_p;
      |                                  ^
%Error: Exiting due to