What version of gRPC and what language are you using?

Grpc.Tools v1.7.3 from the C# NuGet

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

Windows 10 64-bit

What runtime / compiler are you using (e.g. python version or version of gcc)

Microsoft Visual Studio Professional 2017 v15.4.3

What did you do?

Tried providing protoc with --grpc_out=%output_path% --grpc_opt=base_namespace and --grpc_out=base_namespace:%output_path%.

What did you expect to see?

Get the generated service files sorted into the same folder structure analogous to --csharp_opt=base_namespace.

What did you see instead?

The option is not available. Without the option, every service file is put into the base output folder without any structure, leading to conflicts in more complex projects with a lot of services. Also leading to a not very nice overview.