inessential by Brent Simmons

How Not to Crash #8: Infrastructure

Even if you think your app is crash-free, you need to collect crash logs — because there’s no such thing as crash-free: it can only be free of known crashing bugs.

There are a few different services for this, and the ones I’ve tried are pretty good, so I’m not going to make a specific recommendation.

But there are a few things it should do:

  1. Crash logs should be collected without a user having to find them and send them to you. It should be automatic-ish (users should probably be prompted, if on OS X; on iOS nobody seems to expect a prompt).

  2. There should be a way to group crash logs, and you should get a total for each group, so you know which ones are frequent and which aren’t.

  3. You should be able to mark a group as resolved.

It’s not enough, of course, just to collect crash logs. You should look at them regularly. (I look at crash logs every morning.)

Bug tracker

Have one.

For my personal projects I use a combination of Lighthouse, OmniOutliner, and pen-and-paper — but you should use whatever works for you, as long as your crashes get into your bug tracker and don’t get lost.

(Lighthouse is a good bug tracker. For mapping out big new features or entire apps I like OmniOutliner, where I can build a tree of things-to-do. For short-term things — for the 10 steps needed to complete a single task — I like pen and paper, since it’s tiring to rely on short-term memory, since pen and paper doesn’t disturb the on-screen context.)

Errors and warnings

Xcode by default doesn’t turn on enough errors and warnings. I strongly recommend Peter Hosey’s set.

The point is to remove doubt from your code.

I go a step further, which I also recommend: I turn on treat warnings as errors. This means that, yes, I can’t even debug locally if there’s a warning — but the discipline is worth it. It means that whenever my app is actually running, there are not even any warnings.


Instruments is wonderful. It’s a very good idea to check how much memory your app allocates, and it’s super-important to check for leaks.

And if you’re getting crashes, it’s a good idea to use the Zombies tool. Your problem might not be related to zombies, but, when in doubt, it’s worth ruling out.