What version of protoc is supported?

[positron]

I was getting com.google.protobuf.RuntimeVersion not found (See #10976). To fix it I downgraded protoc to 25.2 as I saw breaking changes in 26.

I'm not using gradle or maven (this is a clojure project), so I have no idea how to determine what version of protoc I'm supposed to be using.

[kannanjgithub]

You can find com.google.protobuf:protoc version in the README for the version you are using (1.62.2) here https://github.com/grpc/grpc-java/blob/v1.62.2/README.md#generated-code which is

<protocArtifact>com.google.protobuf:protoc:3.25.1:exe:${os.detected.classifier}</protocArtifact>

The protoc version can be inferred from the Protobuf Java minor version number, so that gives you 25.1. Things broke for you with protoc 26 since it is a higher major version of protoc. 25.2 still worked for you since it is the same major version of protoc so the code generated using it is still compatible with com.google.protobuf:protobuf-java 3.25.1 pulled by your grpc-java version.

[positron]

Ahh that's how you figure it out, ok thank you for that decoder ring.

Keeping the issue open in case you want to spell that out in the README right there. I know this is at least the second issue about it.

[kannanjgithub]

It doesn't really belong in the gRPC release README but in the protoc libraries' release which does mention about the versioning scheme for protoc vs the language runtime binaries.