verilator/test_regress/t/t_class_class.out

%Error-UNSUPPORTED: t/t_class_class.v:12:4: Unsupported: class within class
   12 |    class SubCls;
      |    ^~~~~
                    ... For error description see https://verilator.org/warn/UNSUPPORTED?v=4.201
%Error: Exiting due to