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Comment by viraptor | Hacker News Reader

Depends what you're working on. Stopped in an unfortunate place? That one element didn't get turned off and burned out. Or the motor didn't stop. Or the crucial interrupts got missed and your state is now reset. Or...

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are there debugging tools specifically for situations like that? do you just write code to test manually? How do you ensure dev builds don't break stuff like that even without considering debugging?

The most useful tool is a full tracing system (basically a stream of run instructions you can use to trace the execution of the code without interrupting it), but unfortunately they're quite expensive and proprietery, and require extra connections to the systems that do support them, so they're not particularly commonly used. Most people just use some kind of home-grown logging/tracing system that tracks the particular state they're interested in, possibly logged into a ringbuffer which can be dumped when triggered by some event.

like a perf trace?

You ensure dev builds don't break stuff like that with realtime programming techniques. Dev tools exist and they're usually some combination of platform specific, expensive, buggy, and fragile.

printf and friends are fantastic when applicable. Sometimes the cost to even do an async print or even building in any mode except stripped release is impossible though, which usually leads to !fun!.

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