thread/fork grpc errors

Summary

Jobs like https://gitlab.com/celduin/bsps/example-app/-/jobs/554435318 have lots of E0515 13:36:45.682584029 3021 fork_posix.cc:63] Fork support is only compatible with the epoll1 and poll polling strategies

New versions of grpc don longer error, https://github.com/grpc/grpc/blob/master/src/core/lib/iomgr/fork_posix.cc#L70

But OS's like ubuntu 19.10 still have the old grpc in there, python3-grpcio packages. The system packages are advantages over pip for arm as pip dose not have wheels for grpc on arm platforms.

Steps to reproduce

Create a docker image like https://gitlab.com/celduin/crash/docker-images/-/blob/master/dockerfiles/dockerfile.buildstream2 and run something like FD or something that builds on top of it.

What is the current bug behavior?

E0515 13:36:45.682584029 3021 fork_posix.cc:63] Fork support is only compatible with the epoll1 and poll polling strategies