

Ask HN: How do you get a grip on phantom errors? - jupiter

Most of us already had it: you thought all errors in your app have finally been ironed out and then someone sends you an ugly screenshot showing an even more ugly error you cannot reproduce. He's not tech savvy enough to tell you details about his system config and cannot reliably reproduce the error himself. But the screenshot shows: it's out there. How do you get a grip on that?
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psyklic
I've had this happen many times on random users' systems. If the user is nice
enough to work with you (and they were in my case since they were caught pre-
deployment in contract work), you can often ask them to try new things with a
dev build for instance.

The main key is to reproduce the errors on your system, so just try a bunch of
wacky things like different screen resolutions, memory constraints, database
configurations, etc. Continually look at the code and brainstorm what might
cause that issue -- there are a limited number of code paths -- and try to
cause the constraints in your code. It's definitely very specific to the
individual situation.

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jacquesm
Without the screenshot and an idea of the applications state at that moment
that's kind of hard to answer.

What you could do, is figure out the IP address of the user (that shouldn't be
too hard), then go back into the log files and check all their actions one by
one rebuilding the state up to the moment of the bugs occurrence.

Chances are that you'll be able to reproduce it that way, even if the user is
clueless.

This little trick saved my ass a couple of times.

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tallanvor
Mark it as 'unable to reproduce' and don't worry too much about it until you
get enough information to track down the cause. It sort of sucks, but if very
few users are seeing the problem, sometimes it's not worth the effort unless
you get a clear lead as to the cause of the problem.

