%Error: t/t_class_param_virtual_bad.v:23:28: Illegal to call 'new' using an abstract virtual class 'ClsVirt' (IEEE 1800-2023 8.21)
                                           : ... note: In instance 't'
   23 |       ClsVirt#(VBase) cv = new;   
      |                            ^~~
        ... See the manual at https://verilator.org/verilator_doc.html?v=latest for more assistance.
%Error: t/t_class_param_virtual_bad.v:13:11: Illegal to call 'new' using an abstract virtual class 'VBase' (IEEE 1800-2023 8.21)
                                           : ... note: In instance 't'
   13 |       t = new;
      |           ^~~
%Error: Exiting due to