Sure, and of course this is the essence of printf-debugging. You probably have a rough idea where the problem is, so throw in some printf statements to narrow i

Sure, and of course this is the essence of printf-debugging. You probably have a rough idea where the problem is, so throw in some printf statements to narrow it down, then maybe a 2nd set/etc to further narrow it as needed. A brute force (non-targetted) binary search may always be an option if you have a problem where you don't even know where to look.