[iOS] Fabric component descriptor compilation errors with New Architecture enabled (v0.12.0)

[sinhong2011]

Before submitting a new issue

• I tested using the latest version of the library, as the bug might be already fixed.
• I tested using a supported version of react native.
• I checked for possible duplicate issues, with possible answers.

Bug summary

When building an iOS app with React Native's New Architecture enabled, the Fabric implementation of react-native-bottom-tabs v0.12.0 fails to compile due to missing or incorrectly named component descriptor types.

Library version

0.12.0

Environment info

Package	Version
react-native-bottom-tabs 0.12.0
react-native 0.81.4
expo 54.0.11
react 19.1.0
Platform iOS
New Architecture ✅ Enabled

Steps to reproduce

1. Create a new Expo project with SDK 54 (React Native 0.81.4)
2. Enable New Architecture in app.config.ts:

export default ({ config }: ConfigContext): ExpoConfig => ({
  ...config,
  newArchEnabled: true,
  // ... other config
});

4. Install react-native-bottom-tabs@0.12.0
5. Run pod install in the ios directory
6. Run expo run:ios or build the iOS app

Reproducible sample code

Same as Steps to reproduce

[thedev132]

@sinhong2011 how were you able to solve this? I'm experiencing the same issue

[DvzZDev]

@sinhong2011 how were you able to solve this? I'm experiencing the same issue

+1

[okwasniewski]

This PR will fix it, working on 0.12.1: #441

[okwasniewski]

0.12.1 has been released, closing

[thedev132]

@okwasniewski The build succeeds but now I'm running into a run time error of:

ERROR [runtime not ready]: Invariant Violation: Tried to register two views with the same name RNCTabView

@DvzZDev are u experiencing the same or is this just an issue with my setup? I've cleared caches and everything before building.

[okwasniewski]

@thedev132 Try clearing all build folders because you might still get old codegen files

[thedev132]

I've deleted all build folders, Xcode deprived data, node_modules + fresh install of packages and no luck currently.

[okwasniewski]

Can you try on fresh project to double check if the issue lays on the package side or some build cache? This will be very helpful @thedev132

I was able to spin up a new project with Expo SDK 54

[thedev132]

I seem to have gotten it working on a fresh project. Must be something wrong with my current app setup then as I still see the error there but not on the fresh project. Thank you so much for all your help!

[thedev132]

@okwasniewski I identified the issue! It only seems to be causing this error if I import react-native-bottom-tabs as I was trying to use the useBottomTabBarHeight hook. Hope that helps!