Xcode 在调试时一直暂停

Question

I only have a very small defined set of breakpoints (none of them symbolic breakpoints). But when I run my iOS app on my iPod Touch (model MC086LL, version 4.2.1), Xcode continually breaks in random spots. And on top of that, it doesn't break on my breakpoints.

The debugger works fine when I run the app in the simulator.

Any tips on how I can get this working correctly?

Answer 1

go to the exceptions tab and see if the "All Exceptions" breakpoint is enabled (blue is solid as opposed to opaque) either delete or disable that breakpoint if its enable

I believe this is enabled and thats why it "pauses randomly"

Here's how to re-enable in case you delete it and want it back. Open the sixth tab in your project explorer, in the bottom left corner tap + -> Add exception breakpoint -> Done. This will add an exception handler that will stop your app on the very method call that crashes the app.

Answer 2

This can happen when your symbols are corrupted in your build files. Finding cache files like the "Derived Data" folder for the project or the main Xcode cache file, and deleting it can frequently fix a variety of problems, especially with break-points and editor-debugger interaction.

If your "Derived Data" folder location under Preferences -> Locations is set to "Relative" then the "Derived Data" folder is next to the project file. Find the "Derived Data" folder next to your project file, delete the "Derived Data" folder, re-run your debug session.

If your Preferences -> Locations has the "Derived Data" location set to "Default" it will be in your home folder location:

~/Library/Developer/Xcode/DerivedData

where ~/ represents the root of your home folder. Find the "Derived Data" folder, delete the "Derived Data" folder, re-run your debug session.

If this still does not fix the problem, be aware that Xcode can exhibit all manner of strange behavior when it's "main" cache file is corrupt. That file is located here:

~/Library/Caches/com.apple.dt.Xcode

and is safe to delete as Xcode will recreate that as well. I would recommend quitting and re-running Xcode when that one is deleted.

Xcode is a bit buggy and many of the problems are exacerbated by file data handling bugs that cause it to corrupt it's own caches... once the cache files are corrupt 'cascade failures' are common. Deleting the caches are a good broad-spectrum antibiotic approach when seeing Xcode weirdness and can save considerable time in diagnosing Xcode problems.