This project is a minimal bare React Native repro for the React Navigation WeakRef crash in nested navigation.

1. Install dependencies:

npm install

2. Confirm Android is using legacy architecture (this is required for the missing WeakRef runtime):

• android/gradle.properties contains newArchEnabled=false

3. Start Metro in one terminal:

npm start

4. Run Android in another terminal:

npm run android

By default, this project already runs in a runtime where WeakRef is unavailable (Legacy Architecture). If your environment unexpectedly has WeakRef, you can optionally force it missing in index.js:

(globalThis as any).WeakRef = undefined;

Keep the polyfill disabled in index.js:

// import './weakRefPolyfill';

1. Open the app.
2. Go to the Other tab.
3. Tap Navigate to nested stack screen.

The app crashes because nested navigation consumes params in @react-navigation/core and calls new WeakRef(...) in a runtime where WeakRef is missing:

In this repo, missing WeakRef is the default runtime behavior. The forcing line in index.js is optional.

In index.js, enable the startup polyfill:

import './weakRefPolyfill';

Recommended state:

// (globalThis as any).WeakRef = undefined;
import './weakRefPolyfill';

With the same navigation steps, the app should no longer crash, and you should see a warning log from the polyfill on startup.