[grpc-io] gRPC-Python Stub Version Compatibility Enforcement

[Xuan Wang]

Hi gRPC Python users,

We're making an important change to enforce the version requirement between gRPC generated stub code and the grpcio library:

Key Change

Generated stubs must be used with the same or higher version of the gRPC library. We're adding a run time check for this requirement inside the generated stubs to enforce this requirement going forward.

Why

The version requirement was not enforced before and caused issues when we introduced backward-compatible changes to stub code. This change will help us prevent such issues as we continue to develop gRPC Python. 

Timeline

A runtime check will be added soon, initially printing a warning if there is a version mismatch.

The warning will become an error in v1.65.0, scheduled for release on June 25, 2024.

Please let us know if you have any concerns or questions.

Best,

Xuan