%Error: t/t_var_bad_sv.v:7: Unexpected 'do': 'do' is a SystemVerilog keyword misused as an identifier.
        ... Suggest modify the Verilog-2001 code to avoid SV keywords, or use `begin_keywords or --language.
   reg do;
       ^~
%Error: t/t_var_bad_sv.v:8: Unexpected 'do': 'do' is a SystemVerilog keyword misused as an identifier.
   mod mod (.do(bar));
             ^~
%Error: t/t_var_bad_sv.v:8: syntax error, unexpected '(', expecting ')'
   mod mod (.do(bar));
                ^~~
%Error: Exiting due to