Exceptions thrown without stack traces

[blaugold]

package:grpc uses StreamController.addError and Completer.completeError in a number of places without providing a stack trace. This makes it difficult to debug GrpcErrors.

Repro steps

1. Clone git clone https://github.com/grpc/grpc-dart
2. Go to example/helloworld
3. Apply the following changes:

   diff --git a/example/helloworld/bin/client.dart b/example/helloworld/bin/client.dart
   index 4ec8e8e..deccead 100644
   --- a/example/helloworld/bin/client.dart
   +++ b/example/helloworld/bin/client.dart
   @@ -37,8 +37,9 @@ Future<void> main(List<String> args) async {
          options: CallOptions(compression: const GzipCodec()),
        );
        print('Greeter client received: ${response.message}');
   -  } catch (e) {
   +  } catch (e, s) {
        print('Caught error: $e');
   +    print('Stack trace: $s');
      }
      await channel.shutdown();
    }
   diff --git a/example/helloworld/bin/server.dart b/example/helloworld/bin/server.dart
   index a2b491c..3e920a5 100644
   --- a/example/helloworld/bin/server.dart
   +++ b/example/helloworld/bin/server.dart
   @@ -20,6 +20,7 @@ import 'package:helloworld/src/generated/helloworld.pbgrpc.dart';
    class GreeterService extends GreeterServiceBase {
      @override
      Future<HelloReply> sayHello(ServiceCall call, HelloRequest request) async {
   +    throw UnimplementedError();
        return HelloReply()..message = 'Hello, ${request.name}!';
      }
    }

4. Start bin/server.dart
5. Run bin/client.dart

Expected result: Error thrown by package:grcp includes stack trace.

Actual result: Stack trace is empty:

Caught error: gRPC Error (code: 2, codeName: UNKNOWN, message: UnimplementedError, details: [], rawResponse: null, trailers: {})
Stack trace: 

[blaugold]

@lrhn Looks to me like https://dart-review.googlesource.com/c/sdk/+/380780 would fix this issue. 😊 Is that the case?

[lrhn]

Seems likely from the description. Let's see if it's something we want to land, and won't break too many fragile tests. For now it seems to work at least.