Ken Raffenetti

Hydra is not the only PMI1/PMI2 implementation in use in the wild. I don't think extending it buys us anything.

So add a 4th and 5th put/get implementation?

> > So add a 4th and 5th put/get implementation? > > No. Just one put/get with hex encoding and maximum value length (the fall back version) and another put/get...

> You will create `put_binary|get_binary` anyway, right? My point is to create that in a general way rather than tie it to the PMIx in its design. We can just...

Fixed in #5685.

> AFAICS, #5685 does **not** add the `TYPE(C_PTR)` interface. What am I missing that this issue was closed? You are right. This was closed by mistake.

> `MPI_Comm_spawn` need return an inter communicator. How would that be possible if the spawned processes include non-MPI processes? I believe OpenMPI added a non-standard hint to support non-MPI processes....

> Some libraries, like libibverbs, are not fork safe in all instances. Some links about libibverbs and fork support: https://www.rdmamojo.com/2012/05/18/libibverbs/#Fork_safe https://www.rdmamojo.com/2012/05/24/ibv_fork_init/

Yes, I think adding it is a good idea. Open MPI uses "ompi_non_mpi" as the key. So maybe "mpich_non_mpi"?

> UCX's name string does not fit inside `MPI_MAX_PORT_NAME`, which is only `256`. What to do? Add it to the ABI wishlist for one 😅.