Description
Description
Description
I’m encountering an intermittent crash on iOS when running my React Native app using react-native-reanimated. The crash doesn't happen consistently, but it occurs occasionally during normal usage. It seems related to the native folly::dynamic::hash() call via ShadowNode::clone().
This crash occurs on real iOS devices.
Stack Trace Screenshot
Please find the crash log screenshot below:
Key lines:
EXC_BAD_ACCESS KERN_INVALID_ADDRESS 0x0000000000000000
folly::dynamic::hash() const + 490
ShadowNode::clone(facebook::react::ShadowNodeFragment const&) + 144
reanimated::cloneShadowTreeWithNewPropsRecursive(...)
Steps to reproduce
EXC_BAD_ACCESS KERN_INVALID_ADDRESS 0x0000000000000000
folly::dynamic::hash() const + 490
ShadowNode::clone(facebook::react::ShadowNodeFragment const&) + 144
reanimated::cloneShadowTreeWithNewPropsRecursive(...)
- This seems to be a native-level crash related to
folly::dynamicbeing used as a key in an unordered map. - I’m not directly using folly, but I believe it's used internally by Reanimated or React Native core.
- I suspect a
nullor improperly initialized dynamic value may be passed during ShadowNode cloning.
Reanimated Setup
- Reanimated plugin added in
babel.config.js - Ran
npx react-native-reanimated patch - Linked properly with CocoaPods (
pod installdone)
What I've Tried
- Cleaned build:
npx react-native-clean,xcodebuild clean - Rebuilt the app multiple times
- Crash still happens occasionally, only on iOS, not Android
Additional Notes
- This seems to be a native-level crash related to
folly::dynamicbeing used as a key in an unordered map. - I’m not directly using folly, but I believe it's used internally by Reanimated or React Native core.
- I suspect a
nullor improperly initialized dynamic value may be passed during ShadowNode cloning.
Request
Please let me know:
- If this is a known issue
- Any workaround or patch
- If I can provide a minimal repro (currently it's hard to reproduce consistently)
Snack or a link to a repository
This issue occurs intermittently on a real iOS device and involves a crash inside native code (folly::dynamic::hash() via ShadowNode::clone). Since the crash involves React Native Fabric internals triggered via react-native-reanimated, it cannot be reproduced in Snack (which does not support native modules or Hermes). Due to the native nature and randomness of this crash, creating a minimal reproduction repo is extremely difficult. However, I’ve attached the crash log screenshot and full environment info to help with investigation.
Reanimated version
^3.17.1
React Native version
0.79.1
Platforms
iOS
JavaScript runtime
None
Workflow
React Native
Architecture
Fabric (New Architecture)
Build type
Debug app & production bundle, Release app & production bundle
Device
Real device, iOS simulator
Host machine
macOS
Device model
iphone 12 , iphone 6s, iphone 7
Acknowledgements
Yes