Fix README typo (---go-grpc_out -> --go-grpc_opt)

[shomron]

Fixes typo in README for protoc-gen-go-grpc regarding how to disable the new require_unimplemented_servers compatibility behavior.

Signed-off-by: Oren Shomron shomron@gmail.com

[dfawley]

I believe what we have is correct. If you want to use the opt flag, you'd still need to use out to specify the output directory:

protoc --go-grpc_opt=require_unimplemented_servers=false[,other options...] --go-grpc_out=.

[dfawley]

(Let me know if I'm mistaken and you're seeing errors with the suggested usage as-is.)

[shomron]

@dfawley thanks for looking at this! I see, this seems to be a matter of:

protoc --go-grpc_out=paths=source_relative,require_unimplemented_servers=false:. example.proto

vs.

protoc --go-grpc_out=. --go-grpc_opt=paths=source_relative,require_unimplemented_servers=false example.proto

I was following the example in the gRPC / Go quickstart which has the options broken apart, and trying to combine that with the syntax from this README didn't work. I have to say I'm having trouble tracking down the documentation for these various syntax options - do those exist anywhere?

[dfawley]

I have to say I'm having trouble tracking down the documentation for these various syntax options - do those exist anywhere?

I have to admit I had a hard time with this as well, and only, in fact, learned the difference between opt and out a week or two ago. I think the documentation of protoc and its plugins is lacking (or hiding somewhere).