python protobuf (upb) and subinterpreter support

[Lars Klein]

Hi,

we use python-protobuf in our python code that makes use of subinterpreters. We realized that the default implementation switches from upb to native python. The module import for upb fails with:

ImportError: module google._upb._message does not support loading in subinterpreters

According to https://github.com/protocolbuffers/protobuf/issues/10143 there should be no global state in upb anymore. Is there another reason the module does not support subinterpreters or has it just not been enabled yet?

thanks and best regards,

Lars