PluginController.swift Assertion failed / iOS

[MazenCoder]

After connecting to bluetooth i got this error:

flutter_reactive_ble/PluginController.swift:86: Assertion failed Runner[36443:1970108] flutter_reactive_ble/PluginController.swift:86: Assertion failed

[JKornberg]

I'm having a similar issue:

flutter_reactive_ble/PluginController.swift:153: Assertion failed
* thread #1, queue = 'com.apple.main-thread', stop reason = Assertion failed
    frame #0: 0x0000000191969060 libswiftCore.dylib`_swift_runtime_on_report
libswiftCore.dylib`_swift_runtime_on_report:
->  0x191969060 <+0>: ret
libswiftCore.dylib`_swift_reportToDebugger:
    0x191969064 <+0>: b      0x191969060               ; _swift_runtime_on_report
libswiftCore.dylib`_swift_shouldReportFatalErrorsToDebugger:
    0x191969068 <+0>: adrp   x8, 323753

However I"m also unable to successfully connect on iOS

[JKornberg]

I noticed I'm getting my crash when the connected bluetooth device goes to sleep. Here is the code for my connect function:

  connectToDevice(DiscoveredDevice device) async {
    try {
      await _connectionStateSubscription.cancel();
    } catch (error) {
      print(error);
    }
    _connectionStateSubscription = ble
        .connectToDevice(
      id: device.id,
      servicesWithCharacteristicsToDiscover: {
        service: [characteristic]
      },
      connectionTimeout: const Duration(seconds: 2),
    )
        .listen((connectionState) {
      print("New connection state: $connectionState");
      if (connectionState.connectionState == DeviceConnectionState.connected) {
        _device.sink.add(device);
        _connectionState.add(connectionState);
        writeResult(label: "Connected", value: "Connected to device");
      } else {
        _device.sink.add(null);
        _connectionState.add(null);
        writeResult(label: "Disconnected", value: "Lost connection to device");
      }
    }, onError: (dynamic error) {
      print("ERROR: " + error.toString());
      _connectionState.add(null);
    });
  }

[werediver]

I solved it by changing the : assert(false); to print("");
open the xcode and change: -> else {assert(false) return} to: -> else {print(""); return}

This is not a solution in the slightest. The assert is there for a reason. If it triggers (which only happens in debug builds), it means the code is in an invalid state. In this case the invalid state may be caused by a overly aggressive (rapid) sequence of API calls (which should never cause issues, ideally; in practice it can, though 😞).

[lgozalvez]

Same issue here :(

It is also a random issue for us.

flutter_reactive_ble/PluginController.swift:89: Assertion failed
flutter_reactive_ble/PluginController.swift:89: Assertion failed
* thread #1, queue = 'com.apple.main-thread', stop reason = Assertion failed
    frame #0: 0x000000018f4d3eac libswiftCore.dylib`_swift_runtime_on_report
libswiftCore.dylib`_swift_runtime_on_report:
->  0x18f4d3eac <+0>: ret    
libswiftCore.dylib`_swift_reportToDebugger:
    0x18f4d3eb0 <+0>: b      0x18f4d3eac               ; _swift_runtime_on_report
libswiftCore.dylib`_swift_shouldReportFatalErrorsToDebugger:
    0x18f4d3eb4 <+0>: adrp   x8, 337050
    0x18f4d3eb8 <+4>: ldrb   w0, [x8, #0xef9]
Target 0: (Runner) stopped.
Lost connection to device.

[zellidev0]

Maybe you have to cancel the subscription (stopScanning)? See #283 (comment)

[gonzalolopez-tc]

any update about this issue?

[saibotma]

Also having the same issue.

[vincent290587]

Also having this issue...

[shobhit14gupta]

Also having this issue while multiple subscribing to characteristics.

[lgozalvez]

We all have the same issue...

[remonh87]

Like previously said by @werediver the assert is there for a reason. Instead it would be great if you can help us with providing a reproducible example or additional logging where we can triage it better and determine if it is a mistake by our library

[vincent290587]

I will try to give it a go then ;-)
I am fairly new to (flutter) app dev, so please if you need anything just ask !

Some BLE services send a packet right after connection to set the inital value of the characteristic. This is actually my case.
So the phone should expect an incoming packet very shortly after connecting.

I went in debug mode on my iPhone and did verify that:

• onCharacteristicValueUpdate is called immediately after connecting
• charactertisticValueStreamHandler onListen is called after onCharacteristicValueUpdate

However the characteristicValueUpdateSink is only set in the later function, and if it is not already set in onCharacteristicValueUpdate , the assert will trigger.
It looks like a ce racondition where the stream should be listened to before the connection is really established.

[vincent290587]

If you have a nRF52832 dev kit from Nordic I can provide you with a binary

[sami-kouatli-act]

Any update ?