Friendly placeholder note from your react-native-firebase maintainers 👋
Problem
There is a compiler bug in Xcode 26.4 that miscompiles Swift code that uses async let... language syntax if optimizations are turned on.
Firebase Functions in our native firebase-ios-sdk transitive dependency use this language feature.
Xcode 26.4 miscompiles it during release build optimizations and resulting release app builds will crash.
Workarounds
See this particular comment on the upstream issue for a Podfile workaround: firebase/firebase-ios-sdk#15974 (comment)
Downgrade to Xcode 26.3 for release builds if you cannot use that workaround, or hopefully Xcode will have a fix soon in 26.5+ as well.
Upstream firebase-ios-sdk Fix Coming
Also, firebase-ios-sdk's next release should contain a workaround to avoid using that language feature, follow related upstream PR here firebase/firebase-ios-sdk#15991
We will issue a release here with that firebase-ios-sdk update when it is available (currently scheduled for second week of April), but it will be after a breaking change release here, perhaps meaning that you will not get the fix quickly - you may be stuck on an incompatible combination for a while. I am not aware of any incompatibilities with react-native-firebase v23.x.x and the upcoming firebase-ios-sdk release so it should be okay to mix the new version in.
What to do if you cannot upgrade react-native-firebase quickly
So, If you are temporarily blocked from updating react-native-firebase but need the firebase-ios-sdk fix once that upstream PR is merged and released, it is the perfect time to use our manual override for firebase-ios-sdk version temporarily in your project until you can adopt current react-native-firebase versions: https://rnfirebase.io/#ios
Friendly placeholder note from your react-native-firebase maintainers 👋
Problem
There is a compiler bug in Xcode 26.4 that miscompiles Swift code that uses
async let...language syntax if optimizations are turned on.Firebase Functions in our native firebase-ios-sdk transitive dependency use this language feature.
Xcode 26.4 miscompiles it during release build optimizations and resulting release app builds will crash.
Workarounds
See this particular comment on the upstream issue for a Podfile workaround: firebase/firebase-ios-sdk#15974 (comment)
Downgrade to Xcode 26.3 for release builds if you cannot use that workaround, or hopefully Xcode will have a fix soon in 26.5+ as well.
Upstream firebase-ios-sdk Fix Coming
Also, firebase-ios-sdk's next release should contain a workaround to avoid using that language feature, follow related upstream PR here firebase/firebase-ios-sdk#15991
We will issue a release here with that firebase-ios-sdk update when it is available (currently scheduled for second week of April), but it will be after a breaking change release here, perhaps meaning that you will not get the fix quickly - you may be stuck on an incompatible combination for a while. I am not aware of any incompatibilities with react-native-firebase v23.x.x and the upcoming firebase-ios-sdk release so it should be okay to mix the new version in.
What to do if you cannot upgrade react-native-firebase quickly
So, If you are temporarily blocked from updating react-native-firebase but need the firebase-ios-sdk fix once that upstream PR is merged and released, it is the perfect time to use our manual override for firebase-ios-sdk version temporarily in your project until you can adopt current react-native-firebase versions: https://rnfirebase.io/#ios