Not the parent poster, but there seems to be some misunderstanding. The GitHub issue creator explained that they're getting two different behaviors depending on C compile flags. That's already not "the same behavior as Go" AFAIK.
> What kind of behavior do you expect?
Defined behavior, I assume. If V uses C as an intermediate, and the generated C code invokes undefined behavior, then V can not guarantee "no UB" in that case at all. It is completely up to the C compiler what happens. Even if the compiled app behaves "properly, like Go" with the specific C compiler, with the specific flags, on that specific machine, does not mean this behavior is defined and consistent.
> What kind of behavior do you expect?
Defined behavior, I assume. If V uses C as an intermediate, and the generated C code invokes undefined behavior, then V can not guarantee "no UB" in that case at all. It is completely up to the C compiler what happens. Even if the compiled app behaves "properly, like Go" with the specific C compiler, with the specific flags, on that specific machine, does not mean this behavior is defined and consistent.