Protoc --ruby_out fails to generate a file with a message that contains a field of type google.protobuf.DescriptorProto

[viacheslav-rostovtsev]

What version of protobuf and what language are you using?
Version: 3.13.0
Language: Ruby

What operating system (Linux, Windows, ...) and version?
Debian 5.7.17-1rodete3 (2020-09-16) x86_64 GNU/Linux

What runtime / compiler are you using (e.g., python version or gcc version)
ruby 2.6.5

What did you do?
Steps to reproduce the behavior:

1. Checkout https://github.com/googleapis/googleapis/blob/master/google/cloud/bigquery/storage/v1beta2/protobuf.proto
   (( the message that cause an issue is:

message ProtoSchema {
  // Descriptor for input message. The descriptor has to be self contained,
  // including all the nested types, excepted for proto buffer well known types
  // (https://developers.google.com/protocol-buffers/docs/reference/google.protobuf).
  google.protobuf.DescriptorProto proto_descriptor = 1;
}

2. run protoc --ruby_out=/tmp/foo protobuf.proto
3. see error --ruby_out: protobuf.proto: proto3 message field google.cloud.bigquery.storage.v1beta2.ProtoSchema.proto_descriptor in file google/protobuf/descriptor.proto has a dependency on a type from proto2 file google/protobuf/descriptor.proto. Ruby doesn't support proto2 yet, so we must fail.

What did you expect to see
ruby code generated at the target directory

What did you see instead?
an error
--ruby_out: protobuf.proto: proto3 message field google.cloud.bigquery.storage.v1beta2.ProtoSchema.proto_descriptor in file google/protobuf/descriptor.proto has a dependency on a type from proto2 file google/protobuf/descriptor.proto. Ruby doesn't support proto2 yet, so we must fail.`

Anything else we should know about your project / environment

[yirutang]

Any updates on this? Thanks.

[zhangskz]

The fix was merged to branch 3.18.x on Wednesday and should be part of the next release.

[zhangskz]

Release of 3.18.x will tentatively happen in a day or two.