go-protoc-bin failed: error executing GoProtocGen command

[johanbrandhorst]

Hi! I'm the maintainer of the grpc-gateway. It seems that something in v0.54.0 broke our protobuf generation. This auto-created PR is failing our bazel build. The error is:

 ERROR: /__w/grpc-gateway/grpc-gateway/runtime/internal/examplepb/BUILD.bazel:29:17: Generating into bazel-out/k8-fastbuild/bin/runtime/internal/examplepb/examplepb_go_proto_/github.com/grpc-ecosystem/grpc-gateway/v2/runtime/internal/examplepb failed: (Exit 1): go-protoc-bin failed: error executing GoProtocGen command (from target //runtime/internal/examplepb:examplepb_go_proto) bazel-out/k8-opt-exec-ST-d57f47055a04/bin/external/rules_go+/go/tools/builders/go-protoc/go-protoc-bin -protoc bazel-out/k8-opt-exec-ST-d57f47055a04/bin/external/protobuf+/protoc -importpath ... (remaining 51 arguments skipped)

Use --sandbox_debug to see verbose messages from the sandbox and retain the sandbox build root for debugging
2025/04/15 16:46:48 file "bazel-out/k8-fastbuild/bin/runtime/internal/examplepb/examplepb_go_proto_/github.com/grpc-ecosystem/grpc-gateway/v2/runtime/internal/examplepb/example_grpc.pb.go" expected from plugin "bazel-out/k8-opt-exec-ST-d57f47055a04/bin/go_grpc_reset_plugin_/protoc-gen-go-grpc" but not created
ERROR: /__w/grpc-gateway/grpc-gateway/runtime/internal/examplepb/BUILD.bazel:29:17 GoCompilePkg runtime/internal/examplepb/examplepb_go_proto.a failed: (Exit 1): go-protoc-bin failed: error executing GoProtocGen command (from target //runtime/internal/examplepb:examplepb_go_proto) bazel-out/k8-opt-exec-ST-d57f47055a04/bin/external/rules_go+/go/tools/builders/go-protoc/go-protoc-bin -protoc bazel-out/k8-opt-exec-ST-d57f47055a04/bin/external/protobuf+/protoc -importpath ... (remaining 51 arguments skipped)

I found this a bit hard to parse, but I think the salient part is

go-protoc-bin failed: error executing GoProtocGen command

It doesn't say what exactly failed, though, so not sure how it broke. Here's the full build log: https://github.com/grpc-ecosystem/grpc-gateway/actions/runs/14474740731/job/40597503943?pr=5472. The command was

$ bazel test //...

[fmeum]

We recently made it an error if a proto plugin fails to create files it claims to create to also masking errors. I don't know of any other changes.

[johanbrandhorst]

Thanks, I'll try and investigate if that is happening in my case.

[ptxmac]

We're seeing a similar issue. I can't post the complete code, but here's a snippet:

go_proto_library(
    name = "some_lib",
    compilers = [
        "//bazel/rules/protobuf/go:go_proto",
        "//bazel/rules/protobuf/go:go_grpc_v2",
    ],
    importpath = "some/custom/import/proto_library",
    protos = [
        "//another/path:common_proto",
        "//another/path:proto_library",
    ],
    deps = [
<  ... snip>
    ],
)

On 0.53.0 this correctly creates:

    ├── common.pb.go
    ├── common_grpc.pb.go
    ├── our_api.pb.go
    └── our_api_grpc.pb.go

But after upgrading to 0.54.0 the _grpc.go files are no longer created

We have other targets that DO work, but this one has a importpath that's different from where the BUILD.bazel file is, so that might be related.

[ptxmac]

After some investigation, I discovered the problem:

• The previous rules_go created a dummy file
• one of the two protos in the target did not have a service, so the grpc compiler created no output

I'm not sure what the solution is, the first proto needs to be compiled with the grpc compiler, and it depends on the 2nd proto. But the change in 0.54.0 requires all compilers to create output for all files

[ptxmac]

Any plans to create a 0.54.1 release with this fix?

[linzhp]

yeah, I can create one later this week

[guw]

@linzhp @fmeum BCR still hast 0.54.0. Can a fix be published? 🙏

For cross-linking: connectrpc/connect-go#846

[linzhp]

Publishing: bazelbuild/bazel-central-registry#4626

Sorry for the delay

[johanbrandhorst]

Fixed my workflow, thank you! grpc-ecosystem/grpc-gateway#5594