%Warning-MODDUP: t/t_mod_dup_bad.v:14:8: Duplicate declaration of module: 'a'
   14 | module a();
      |        ^
                 t/t_mod_dup_bad.v:7:8: ... Location of original declaration
    7 | module a();
      |        ^
                 ... Use "/* verilator lint_off MODDUP */" and lint_on around source to disable this message.
%Warning-MULTITOP: t/t_mod_dup_bad.v:17:8: Multiple top level modules
                                         : ... Suggest see manual; fix the duplicates, or use --top-module to select top.
                                         : ... Top module 'test'
   10 | module test();
      |        ^~~~
                                         : ... Top module 'b'
   17 | module b();
      |        ^
%Error: Exiting due to