There is a new pull request by ahesford against master on the void-packages repository

https://github.com/ahesford/void-packages mpi
https://github.com/void-linux/void-packages/pull/23767

openmpi: update to 4.0.4; python3-mpi4py: update to 3.0.3


A patch file from https://github.com/void-linux/void-packages/pull/23767.patch is attached