Hi Maurice,

Maurice Brémond <Maurice.Bremond@inria.fr> skribis:

> Apparently at the mpich configuration level, using the experimental
> device ch4 instead of ch3 solves the problem : just remove comment on
> "--with-device=ch4:ucx".  Reversely, with mpich 3.4a2 (for which ch4 is
> de default) setting --with-device=ch3 leads to the same failure as with
> 3.3.2.

Nice, we have a way forward.

With the patch below, I have successfully built:

  guix build mumps-openmpi --with-input=openmpi=mpich

and I confirm that despite the name it depends exclusively on MPICH.
:-)

If that’s fine with you I’ll go ahead and commit it; let me know!

> I also checked sock channel for ch3 : with-device=ch3:sock, but then on
> my laptop, scotch tests hang at
>
> mpirun -n 3 ./test_scotch_dgraph_check data/bump.grf
>
> For the moment, there isn't a stable 3.4 version yet for mpich. I had a
> try with the latest 3.4b1 but a test failed...

We’ll see, but having a solution that works with 3.3 and is likely to
work with 3.4 is good.

I guess we should also check whether we’re obtaining the expected
performance.  This builds fine too:

  guix build intel-mpi-benchmarks --with-input=openmpi=mpich

Thank you!

Ludo’.