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376 points turrini | 1 comments | | HN request time: 0.001s | source
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rkharsan64 ◴[] No.42146864[source]
On a general note, I would recommend any new (and experienced!) programmers to master the debugging tools of their ecosystem. I've seen countless experienced developers use printf-based debugging and waste hourse debugging something which could've been easily figured out by setting a breakpoint and stepping through your code. This is also a good way to understand code you're unfamiliar with.

This is one area where I believe a GUI tool is so much better: I can hover over variable names to view their values, expand and collapse parts of a nested structure, edit values easily, and follow execution in the same environment I write my code in.

Sure, it doesn't help much for some scenarios (one I've heard people mention is multithreaded code, where logs are better?), but for most people it's not that far from a superpower.

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mpweiher ◴[] No.42147101[source]
Interesting.

My experience is the opposite: I see developers waste hours stepping through their code a line at a time when a few judiciously placed logs (printfs() are fine, but we can do better) would have told them exactly what they needed in a jiffy.

If you have a fairly shallow bug, that is a single point in your code that always behaves incorrectly, then I find debuggers reasonably effective.

But most of the bugs that I see aren't that shallow, with code misbehaving when the context is just so and perfectly fine otherwise. In those cases, I need to see lots of different invocations and their context. The debugger is like trying to drink the information ocean I need through a straw. A mostly plugged straw.

I wonder what makes our experiences so different? Do you unit test a lot? Particularly with TDD? I am guessing that this practice means I just don't get to see a lot of the bugs that a debugger would help me with.

(And it doesn't mean I never fire up the debugger. But it is fairly rare).

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whartung ◴[] No.42149104[source]
I trend more towards print debugging than breakpoints.

To me the beauty of print debugging is you can see the flow, and see it quickly in contrast to the debugger. Simply with the debugger, a lot of the time is spent stepping past (at the moment) superfluous breakpoints.

Step, step, step, step, …, step, step, BANG!

Versus a quick BANG preceded by a trail of debris I can then postmortem. I use both, naturally, but prefer the crashes with a debris field than walking on eggs to potential disaster.

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1. sfink ◴[] No.42152353[source]
Which is why a good reversible debugger is so powerful. (I use rr-project.org and Pernosco but I imagine undo.io is similar.) Don't worry about stopping at the right point. Go back to the critical points over and over again, and go backwards to what generated an input. If you like logs, the debugger has facilities for generating tailored ones. Or manually generate your own debugging session log trail, generating entries throughout the execution in any order, and see them in execution order.