Unwrapping status errors is unexpected

[maratori]

What version of gRPC are you using?

1.74.2

What version of Go are you using (go version)?

go version go1.24.4 darwin/arm64

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

macOS Sequoia 15.6

What did you do?

I want to wrap a gRPC status error and be able to receive the original proto message. This PR #6150 makes it unexpectedly hard because I can not use status.FromError.

Here is an example:

err := fmt.Errorf("prefix: %w", status.Error(codes.NotFound, "description"))

raw := status.Convert(err).Proto()
println(raw.Message) // prefix: rpc error: code = NotFound desc = description

err = status.Convert(err).Err()
println(err.Error()) // rpc error: code = NotFound desc = prefix: rpc error: code = NotFound desc = description

What did you expect to see?

I expect to see the original message from the server.

println(raw.Message) // description

What did you see instead?

I see the full wrapped error message.

Workaround

I have to use a custom unwrapper to get the original proto message.

func Original(err error) *status.Status {
	var gs interface{ GRPCStatus() *status.Status }
	if errors.As(err, &gs) {
		grpcStatus := gs.GRPCStatus()
		if grpcStatus != nil {
			return grpcStatus
		}
	}
	return status.New(codes.Unknown, err.Error())
}