koobas.hobune.stream
Why does Unity for iPhone disable debug symbols by default and how should we turn it back on?
I recently ran into the problem of submitting an app to Apple that used Unity and iOS 4.3 as base SDK. It ran perfectly on our own devices but it crashed immediately after launch on Steve's iphone. They added a couple of crash logs for me to check out.
Of course to symbolicate the crash log I need DWARF symbols, but apparently Unity by default turns off generating debug info (why?). I switched it on in my project settings and rebuilt the app. Fortunately the UUID hadn't changed so I should be able to use the newly generated symbols with the crash log, right?
Turns out the dSYM files didn't contain any debug info at all. After some inspection I found out that Unity adds some extra linker flags "-Wl,-S,-x". This strips the binary of debug symbols before xcode exports the dSYM folder. Removing this flag unfortunately changes the UUID of the app, so using these symbols to make sense of the crash log that was sent might be a bad idea.
I since found out that I wasn't the only one with the problem so I just resubmitted our game with iOS 4.2. But it has left me wondering why Unity by default makes it impossible for us to make sense of crash logs. Is there some other way we should be debugging our apps?
And why does Unity set those specific flags? Could I not remove those flags and just enable "Strip Debug Symbols During Copy" option to do the same thing but at the appropriate stage?
I hope someone can shed some light on this
I switched it on in my project settings and rebuilt the app
How do you turn the debug symbols on?
These flags save you couple of megabytes on distribution size. When you need to analyze crash just rebuild app without that flag. Code symbol locations will remain the same.
Thanks for the answer! Just want to make sure: removing the -S option changes the UUID of the binary, can you really still guarantee the symbol locations are the same? Also, does stripping the symbols in a post processing step (like xcode does by default) not do exactly the same as the -S linker option?
Except when dealing with IAP crack and receipt verification... the app from the app store and a debug install are not the same. I'm left with a stack trace and can't symbolicate it. And that dsym information is stored locally, it doesn't come out with the app store release does it?
I've been able to correctly generate the dSY$$anonymous$$ and still keep the distribution size the same by setting the following configuration on project settings (for Release):
Build Options: Debug Information Format: "DWARF with dSY$$anonymous$$ file"
Deployment: Deployment Postprocessing: Yes, Strip Symbols During Copy: Yes, Strip Linked Product: Yes, Use Separate Strip: Yes
Linking: Remove "-Wl,-S,-x" from Other Linker Flags
Apple LLV$$anonymous$$ (or GCC) Code Generation: Generate Debug Symbols: Yes
You can use this code to automatically adjust your project after Unity generates it: https://gist.github.com/Capyvara/5230032
Shipped a couple games with this approach and it seems to be working nicely so far.
I do not know about the reasoning of why these flags are set, but the crash with iOS SDK 4.3 is a known issue currently being investigated. We sent an email to all iOS developers about this:
Dear Unity iOS Developers,
Unfortunately, many (and probably all) Unity iOS applications built with iOS SDK 4.3 are crashing during the App Store Review process while still running successfully on developer's devices. We have contacted Apple regarding this issue and received confirmation that this is of highest priority to them. Our iOS team is working on a solution as well, but due to complex nature of the problem it will take longer than expected to properly resolve. A currently known workaround is to keep using iOS SDK 4.2.
Many users reported that applications built with Xcode 3.2.5 + iOS SDK 4.2 successfully pass the Apple App Store review process currently. OS SDK 4.2 is not publicly available on the iOS Developer site anymore, but it still can be downloaded via direct link. We want to assure you that building final applications with iOS SDK 4.2 provides all the features the Unity iOS run-time supports and is proven to work fine with devices running older generation iOS (3.x-4.2.x) as well as the newer devices running iOS 4.3.x (like iPad 2).
Please feel free to contact us if you have issues releasing your application to the App Store.
Regards,
The Unity Team
Symbolicated iOS crash reports from Unity games explained: http://www.markj.net/ios-crash-reports-unity3d-symbolicate/
