What version of rules_go are you using?

0.24.1

What version of gazelle are you using?

0.22.0

What version of Bazel are you using?

Build label: 3.5.0-homebrew
Build target: bazel-out/darwin-opt/bin/src/main/java/com/google/devtools/build/lib/bazel/BazelServer_deploy.jar
Build time: Thu Sep 3 00:54:35 2020 (1599094475)
Build timestamp: 1599094475
Build timestamp as int: 1599094475

Does this issue reproduce with the latest releases of all the above?

Yes

What operating system and processor architecture are you using?

$ echo $MACHTYPE
x86_64-apple-darwin19

Any other potentially useful information about your toolchain?

No

What did you do?

I have the following directory structure where server is a top level directory in a github repository called repo:

server
├── cmd
│   └── dummy
│       └── main.go
├── idl
│   └── dummy
│       └── dummy.proto
├── pkg
│   └── dummy_gen
│       └── dummy.pb.go
├── go.mod
└── go.sum

dummy.pb.go is generated from the following .proto file

syntax = "proto3";

package dummy_gen;

option go_package = "github.com/veganafro/repo/pkg/dummy_gen";

service DummyService {
    rpc GetDummy(DummyRequest) returns (DummyResponse) {}
}

message DummyRequest {
    string msg = 1;
}

message DummyResponse {
    string rsp = 1;
}

using this protoc command that's executed from the root of the repository.

protoc --proto_path=server/idl \
        server/idl/dummy/dummy.proto \
        --go_out=plugins=grpc:server \
        --go_opt=module=github.com/veganafro/repo

I'm attempting to migrate from Make to Bazel and so far I've added the following BUILD file at the same location as my dummy.proto file:

load("@rules_proto//proto:defs.bzl", "proto_library")
load("@io_bazel_rules_go//proto:def.bzl", "go_proto_library")

proto_library(
    name = "dummy_proto",
    srcs = ["dummy.proto"],
    visibility = ["//visibility:public"],
)

go_proto_library(
    name = "dummy_go_proto",
    compilers = ["@io_bazel_rules_go//proto:go_grpc"],
    importpath = "github.com/veganafro/repo/pkg/dummy_gen",
    proto = ":dummy_proto",
    visibility = ["//visibility:public"],
)

After running bazel build //idl/dummy:dummy_go_proto, I'm seeing that the dummy.pb.go is generated, but it's placed in a subdirectory of bazel-bin.

How can I reproduce the behavior specified by the --go_out=plugins=grpc:server and --go_opt=module=github.com/veganafro/repo flags using Bazel? Specifically, how can I direct Bazel to place the generated dummy.pb.go file in the dummy_gen directory?

What did you expect to see?

I expected to see the generated .pb.go files placed in the directory specified by the go_package option in dummy.proto.

What did you see instead?

I see the .pb.go files placed in a subdirectory of bazel-bin that follows the pattern in importpath.