Actually, it's the other way around. Logging [which is pretty much what printf debugging is] is much more sustainable for long-running nondeterministic programs

Actually, it's the other way around. Logging [which is pretty much what printf debugging is] is much more sustainable for long-running nondeterministic programs. It's far easier to look at a log and say "After 3 hours, this program started giving bad responses for these specific inputs". Debuggers are great when you know where to attach and what to look at, but finding that information out is far easier to do from a log.