Method not found: System.Buffers.ReadOnlySequence when doing grpc-web from iOs Xamarin

What version of gRPC and what language are you using?

Grpc.Net.Client 2.35.0 Grpc.Net.Client.Web 2.35.0

What operating system (Linux, Windows,…) and version?

iOs Xamarin

What did you do?

Simple solution dont work with iOs and Grpc.Net.Client.Web with iOs when trying make simple request, when Andoid version works without issues

What did you expect to see?

Working grpc-web request

What did you see instead?

Status(StatusCode="Internal", Detail="Error starting gRPC call. MissingMethodException: Method not found: System.Buffers.ReadOnlySequence`1<byte> Grpc.Core.DeserializationContext.PayloadAsReadOnlySequence()", DebugException="System.MissingMethodException: Method not found: System.Buffers.ReadOnlySequence`1<byte> Grpc.Core.DeserializationContext.PayloadAsReadOnlySequence() 
at Grpc.Net.Client.StreamExtensions.ReadMessageAsync[TResponse] (System.IO.Stream responseStream, Grpc.Net.Client.Internal.GrpcCall call, System.Func`2[T,TResult] deserializer, System.String grpcEncoding, System.Boolean singleMessage, System.Threading.CancellationToken cancellationToken) [0x004ef] in <d2d9cece439e4d8489b25faa43119c3a>:0 
at Grpc.Net.Client.Internal.GrpcCall`2[TRequest,TResponse].RunCall (System.Net.Http.HttpRequestMessage request, System.Nullable`1[T] timeout) [0x003e3] in <d2d9cece439e4d8489b25faa43119c3a>:0 ") 
at ProtoBuf.Grpc.Internal.Reshape.UnaryTaskAsyncImpl[TRequest,TResponse] (Grpc.Core.AsyncUnaryCall`1[TResponse] call, ProtoBuf.Grpc.Internal.MetadataContext metadata, System.Threading.CancellationToken cancellationToken) [0x0013c] in <69a2f5ff9c0a4440b4f06a1d273a112f>:0 

Anything else we should know about your project / environment?

I use protobuf-net.Grpc for contracts but i doubt error comes from there.

Created repository where i could reproduce issue. https://github.com/valentasm1/grpcissue

[valentasm1]

Can confirm that adding these libraries to iOs project helped and it works now. I must emphasize “IncludeAssets” part which is must be there, so you need to add packages via editing csproj file by hand. So many mentioning in that issue so hopefully it will be solved in future 😃. Closing

 <ItemGroup>
    <PackageReference Include="System.Memory" Version="4.5.4">
      <IncludeAssets>none</IncludeAssets>
    </PackageReference>
    <PackageReference Include="System.Buffers" Version="4.5.1">
      <IncludeAssets>none</IncludeAssets>
    </PackageReference>
  </ItemGroup>

[valentasm1]

Same thing. I dont have time today to try other things, but this case looks very similar to mine 😃. I will try workarounds from there and let you know https://github.com/mono/mono/issues/20805