%Error: t/t_class_extern_bad.v:9:15: Duplicate declaration of task: 'extern nodef'
    9 |   extern task nodef();   
      |               ^~~~~
        t/t_class_extern_bad.v:8:15: ... Location of original declaration
    8 |   extern task nodef();
      |               ^~~~~
        ... See the manual at https://verilator.org/verilator_doc.html?v=latest for more assistance.
%Error-PROTOTYPEMIS: t/t_class_extern_bad.v:8:15: Definition not found for extern prototype 'nodef'
    8 |   extern task nodef();
      |               ^~~~~
                     ... For error description see https://verilator.org/warn/PROTOTYPEMIS?v=latest
%Error-PROTOTYPEMIS: t/t_class_extern_bad.v:9:15: Definition not found for extern prototype 'nodef'
    9 |   extern task nodef();   
      |               ^~~~~
%Error: t/t_class_extern_bad.v:12:6: extern not found that declares 'noproto'
   12 | task Base1::noproto();   
      |      ^~~~~
%Error: Exiting due to