%Warning-IGNOREDRETURN: t/t_func_void_bad.v:26:7: Ignoring return value of non-void function (IEEE 1800-2017 13.4.1)
   26 |       f1(20);
      |       ^~
                        ... Use "/* verilator lint_off IGNOREDRETURN */" and lint_on around source to disable this message.
%Error: Exiting due to