onError not working in dio interceptor about dio

[Alleds]

@zubair999 try to add super.onError(err, handler)

[zubair999]

@zubair999 try to add super.onError(err, handler)

I already tried it but it 's not working. I try print in onError code block but request never there, and if reload the app then it print.

[AlexV525]

Your reproducible code is not minimal, which means hard for us to reproduce the case easily. Please consider setting breakpoints and running the app with the debugger to see it it actually works.

[ykaito21]

I have a similar problem. dio version 5.4.1

Expected Behavior:
After the request fails and triggers onError, the retried request within onError should also throw a DioException if it fails, which should then be caught by the try-catch block within the same onError method. This should allow for custom error handling or logging of the retried request failure.

Actual Behavior:
The retried request within onError triggers the onRequest interceptor again as expected, but if the retried request fails, the try-catch block within onError does not catch the subsequent DioException. This behavior prevents custom error handling for the retried request failure from being executed as intended.

Making a GET request...
onRequest is called
onError is called
onRequest is called

import 'package:dio/dio.dart';

class ErrorInterceptor extends QueuedInterceptor {
  final Dio dio;

  ErrorInterceptor(this.dio);

  @override
  Future<void> onError(
      DioException err, ErrorInterceptorHandler handler) async {
    print('onError is called');
    try {
      // This should throw an error
      await dio.fetch(err.requestOptions);
    } catch (e) {
      // Why cannot I catch the error here?
      print('onError is called again');
    }
    handler.next(err);
  }
}

class RequestInterceptor extends Interceptor {
  const RequestInterceptor();

  @override
  void onRequest(RequestOptions options, RequestInterceptorHandler handler) {
    print('onRequest is called');
    return handler.next(options);
  }
}

class ResponseIntercepter extends Interceptor {
  const ResponseIntercepter();

  @override
  void onResponse(Response response, ResponseInterceptorHandler handler) {
    print('onResponse is called');
    handler.next(response);
  }
}

void main() async {
  var dio = Dio();

  // Add the custom interceptor
  dio.interceptors.addAll([
    const RequestInterceptor(),
    const ResponseIntercepter(),
    ErrorInterceptor(dio),
  ]);

  // Making a GET request
  try {
    print('Making a GET request...');
    Response response =
        await dio.get('https://example.com/this-does-not-exist');
    print(response.data);
  } catch (e) {
    print("Final error: $e");
  }
}