___cxa_current_primary_exception with Xcode 16.3

[SmartHbdev]

Description

The iOS app crashes with Xcode 16.3 (whereas it works fine with 16.2) when FirebaseCrashlytics is included on any iOS version below 18.4.

After investigation, the issue appears to come from libc++.1.dylib, and the problematic symbol is only present in FirebaseCrashlytics.

Reproducing the issue

Use Xcode 16.3, IOS simulator 18.3.1 and add FirebaseCrashlytics

Firebase SDK Version

11.12.0

Xcode Version

16.3

Installation Method

Swift Package Manager

Firebase Product(s)

Crashlytics

Targeted Platforms

iOS

Relevant Log Output

Symbol not found: ___cxa_current_primary_exception
  Referenced from: <F05C8D89-AA32-3C24-8361-486BA2E9C1C0> /Users/leo/Library/Developer/CoreSimulator/Devices/307AB8B3-A8A9-4912-9F98-88A10F02BFD6/data/Containers/Bundle/Application/B16035FC-3A3E-4B33-AB23-558291E84247/KidCal.app/KidCal.debug.dylib
  Expected in:     <FB59D1E0-4DF5-3571-91CF-F5A90235BA68> /Library/Developer/CoreSimulator/Volumes/iOS_22D8075/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 18.3.simruntime/Contents/Resources/RuntimeRoot/usr/lib/libc++.1.dylib
dyld config: DYLD_SHARED_CACHE_DIR=/Users/leo/Library/Developer/CoreSimulator/Caches/dyld/24E263/com.apple.CoreSimulator.SimRuntime.iOS-18-3.22D8075 DYLD_ROOT_PATH=/Library/Developer/CoreSimulator/Volumes/iOS_22D8075/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 18.3.simruntime/Contents/Resources/RuntimeRoot DYLD_LIBRARY_PATH=/Users/leo/Library/Developer/Xcode/DerivedData/KidCal-frsuuarzskyhxjgzsvshrpsalpjx/Build/Products/Debug-iphonesimulator:/Library/Developer/CoreSimulator/Volumes/iOS_22D8075/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 18.3.simruntime/Contents/Resources/RuntimeRoot/usr/lib/system/introspection DYLD_INSERT_LIBRARIES=/Library/Developer/CoreSimulator/Volumes/iOS_22D8075/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 18.3.simruntime/Contents/Resources/RuntimeRoot/usr/lib/libLogRedirect.dylib:/Library/Developer/CoreSimulator/Volumes/iOS_22D8075/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 18.3.simruntime/Contents/Resources/RuntimeRoot/usr/lib/libBacktraceRecording.dylib:/Library/Developer/CoreSimulator/Volumes/iOS_22D8075/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 18.3.simruntime/Contents/Resources/RuntimeRoot/usr/lib/libMainThreadChecker.dylib:/usr/lib/libRPAC.dylib:/System/Library/PrivateFrameworks/GPUToolsCapture.framework/GPUToolsCapture:/Library/Developer/CoreSimulator/Volumes/iOS_22D8075/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 18.3.simruntime/Contents/Resources/RuntimeRoot/usr/lib/libViewDebuggerSupport.dylib DYLD_FRAMEWORK_PATH=/Users/leo/Library/Developer/Xcode/DerivedData/KidCal-frsuuarzskyhxjgzsvshrpsalpjx/Build/Products/Debug-iphonesimulator:/Users/leo/Library/Developer/Xcode/DerivedData/KidCal-frsuuarzskyhxjgzsvshrpsalpjx/Build/Products/Debug-iphonesimulator/PackageFrameworks DYLD_FALLBACK_FRAMEWORK_PATH=/Library/Developer/CoreSimulator/Volumes/iOS_22D8075/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 18.3.simruntime/Contents/Resources/RuntimeRoot/System/Library/Frameworks DYLD_FALLBACK_LIBRARY_PATH=/Library/Developer/C

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[google-oss-bot]

I couldn't figure out how to label this issue, so I've labeled it for a human to triage. Hang tight.

[rizafran]

Thanks for the report, @SmartHbdev. I'm unable to reproduce the issue using Xcode 16.3, but I found a related issue on Apple forum here. Based on the reply, this looks like a bug in Apple.

[SmartHbdev]

Thanks for the follow-up. I investigated the issue using tools like otool, and the crash clearly involves a symbol from the Crashlytics library. When I remove Crashlytics, the crash disappears — with no other code changes.

The crash only happens with Xcode 16.3, while everything works fine with 16.2, so it’s likely something changed on Apple’s side. That said, since the crash points to Crashlytics and it’s part of your SDK, maybe there’s something that could be done on your end to prevent it ?

I had to raise the minimum OS version from 13 to 15 or 16, otherwise the crash doesn’t occur.

[paulb777]

Might be related to Apple dropping support for iOS 13 - see https://developer.apple.com/support/xcode/

[SmartHbdev]

The problem is clearly libc++.1.dylib inside Crashlytics. This framework link libc++ somehow and maybe Apple dropped support for this in iOS version before 18.4 since the crash say it’s missing.

But in iOS 18.4 this key exists and there is no crash. On the other side, Xcode 16.2 can run without issues any projects without any crash.