📜 Description

• After a Flutter hot restart, the old Dart isolate is torn down and its Dart port becomes invalid.
• Android still holds Java/Kotlin callback objects (the recorder’s callbacks) and executes them later on the main thread.
• Those callbacks are Java proxies created via jni that forward into Dart through the now-dead port.
  When the proxy invokes into JNI, libflutter.so dereferences invalid isolate state and crashes (SIGSEGV), often showing PortProxyBuilder.invoke in the stack.

Simple solution

• Wrap every recorder callback with a small guard that checks a generation number.
• Bump that generation when the Flutter engine detaches and before wiring a new recorder.
• Each wrapper captures the generation at creation; if it doesn’t match the current one, it returns immediately and never crosses JNI.
• Close the previous ReplayIntegration during restart so it stops posting work.

💡 Motivation and Context

Fixes crashing on hot-restart on Android

💚 How did you test it?

Manual test

• Check it did not crash after hot restarting
• Check replays are still sent after hot restarting

📝 Checklist

• I reviewed submitted code
• I added tests to verify changes
• No new PII added or SDK only sends newly added PII if sendDefaultPii is enabled
• I updated the docs if needed
• All tests passing
• No breaking changes

🔮 Next steps