annotations.proto was not found or had errors

[jackwootton]

In which file did you encounter the issue?

python-docs-samples/endpoints/bookstore-grpc/http_bookstore.proto

Did you change the file? If so, how?

No.

Describe the issue

Attempting to compile http_bookstore.proto

python -m grpc.tools.protoc --python_out=generated_pb2 --grpc_python_out=generated_pb2 --proto_path=. http_bookstore.proto

Resulted in the error:

google/api/annotations.proto: File not found.
http_bookstore.proto: Import "google/api/annotations.proto" was not found or had errors

Since this example is cited in the Transcoding HTTP/JSON to gRPC guide, which itself is linked from a README.md in this repo:

python-docs-samples/endpoints/bookstore-grpc/README.md

...I think it's reasonable for this example to work.