%Warning-IGNOREDRETURN: t/t_func_void_bad.v:21:7: Ignoring return value of non-void function (IEEE 1800-2023 13.4.1)
   21 |       f1();   
      |       ^~
                        ... For warning description see https://verilator.org/warn/IGNOREDRETURN?v=latest
                        ... Use "/* verilator lint_off IGNOREDRETURN */" and lint_on around source to disable this message.
%Warning-IGNOREDRETURN: t/t_func_void_bad.v:24:9: Ignoring return value of non-void function (IEEE 1800-2023 13.4.1)
   24 |       c.fi();   
      |         ^~
%Error: Exiting due to