OpenMPI 5.0 Ready To Say "Goodbye" To 32-Bit Support
OpenMPI 5.0 plans to ship without 32-bit software support, regardless whether Arm, x86, or for other 32-bit CPU architectures. 32-bit software environments are simply not going to be supported and the OpenMPI build system is set to abort if trying to build for a 32-bit environment.
At this stage the change is just with the build system to block 32-bit builds so if a real need arises it could be reverted after OpenMPI 5.0.0, but the hope by this MPI project is that they can finally retire 32-bit software support in full. If no one complains, the developers will move ahead and gutting the rest of the 32-bit infrastructure/code. The developers found no one willing to step up to maintain the 32-bit support no any real-world users/customers relying on it.
OpenMPI is widely-used in the HPC space that has been 64-bit for a while and in 2023 it's a good move to finally bid farewell to 32-bit support where users can continue relying upon OpenMPI 4.x if really there is such a real-world use remaining. If you are making serious use of MPI / OpenMPI in 2023 and beyond for parallel computing, it's past due to upgrade.