Inability to Modify SpeechClient Endpoint in C++ Client Leads to Global Region Lock

[jiahansu]

Does this issue affect the google-cloud-cpp project?
Yes, the same operations execute successfully in the Python and Node.js clients, yet they encounter failure when attempted with the C++ client

What component of google-cloud-cpp is this related to?
google/cloud/speech/v2

Describe the bug
When using the Google Cloud Speech-to-Text C++ client, it appears impossible to modify the SpeechClient endpoint to use a specific region, resulting in the client defaulting to the global region. This limitation does not exist in the Python and Node.js clients, where modifying the endpoint to target a specific region works as expected.

To Reproduce Steps to reproduce the behavior:

1. Attempt to set the endpoint option for the SpeechClient to a non-global region, such as "asia-southeast1-speech.googleapis.com", using the C++ client library.
2. Configure and execute a Recognize request using the modified client.
   e.g.,

   request.set_recognizer("projects/{project_id}/locations/asia-southeast1/recognizers/_");

3. Observe the error response indicating an expected global resource location rather than the specified regional endpoint.

Expected resource location to be global, but found asia-southeast1 in resource name.

auto options = google::cloud::Options{}.set<google::cloud::EndpointOption>(
  "asia-southeast1-speech.googleapis.com");
auto connection = google::cloud::speech_v2::MakeSpeechConnection(options);
auto client = google::cloud::speech_v2::SpeechClient(connection, options);
// Parse command line arguments.
auto args = ParseArguments(argc, argv);
auto const file_path = args.path;
speech_v2::RecognizeRequest request;

request.set_allocated_config(new speech_v2::RecognitionConfig(args.config));
request.set_recognizer("projects/{project_id}/locations/asia-southeast1/recognizers/_");
request.set_uri("gs://musevision/audio/audio-files/out.wav");

auto response = client.Recognize(request, options);

if (response.status().code() != google::cloud::StatusCode::kOk) {
  //Output: expected resource location to be global, but found asia-southeast1 in resource name.
  std::cerr << "Recognize failed: " << response.status().message() << "\n";
  return 1;
}

Expected behavior
Successfully transcribed the audio file without any errors reported.

Operating system:
macOS 14.3.1

What compiler and version are you using?
Homebrew clang version 17.0.6

What version of google-cloud-cpp are you using?
2.21.0

Additional context Add any other context about the problem here.

[scotthart]

Can you try also setting the google::cloud::AuthorityOption to the same value as your EndpointOption?

auto options = google::cloud::Options{}
    .set<google::cloud::EndpointOption>("asia-southeast1-speech.googleapis.com")
    .set<google::cloud::AuthorityOption>("asia-southeast1-speech.googleapis.com");

And see if that resolves the issue?

[scotthart]

Fixed.