mumps is FTBFS on hppa and powerpc, segfaulting in build-time tests,
https://buildd.debian.org/status/fetch.php?pkg=mumps&arch=powerpc&ver=5.8.2-1&stamp=1776994818&raw=0

The segfault is hard to interpret, but reproducing on powerpc
porterbox suggests mpich and pmix might be the problem

e.g.

(sid_powerpc-dchroot)~/mumps/mumps-5.8.2/examples$ LD_LIBRARY_PATH=~/mumps/mumps-5.8.2/lib mpirun -np 2 ./ssimpletest < input_simpletest_real 2>&1  | head
Fatal error in internal_Init: Internal MPI error!, error stack:
internal_Init(70)...............: MPI_Init(argc=(nil), argv=(nil)) failed
MPII_Init_thread(204)...........:
MPIR_pmi_init(225)..............:
check_MPIR_CVAR_PMI_VERSION(157):  Runtime environment uses unsupported PMI version PMI-1 or PMI-2. Aborting.
Assertion failed in file src/util/mpir_pmi.c at line 338: 0
Fatal error in internal_Init: Internal MPI error!, error stack:
internal_Init(70)...............: MPI_Init(argc=(nil), argv=(nil)) failed
MPII_Init_thread(204)...........:
MPIR_pmi_init(225)..............:

The libpmix2t64 used on powerpc is 5.0.1-4.1
but pmix is now 6.0.0+really5.0.9-3
Indeed, pmix was switch to 64-bit only in 5.0.2-2

But mpich's debian/control declares
Build-Depends:
               libpmix-dev [arm64 ppc64el riscv64 s390x powerpc ppc64 sparc64],
               libpmix-bin [arm64 ppc64el riscv64 s390x powerpc ppc64 sparc64],

i.e. 32-bit powerpc is still listed there in the libpmix-dev dependency,
even though it no longer builds it.

Evidently powerpc needs to be removed from these mpich pmix dependencies.
This would be severity: serious, except that powerpc is not an
official port.


Then there's a mumps test failure on hppa.
But hppa doesn't have the same pmix problem so don't know what's going on
there yet. The hppa mumps error message at
https://buildd.debian.org/status/fetch.php?pkg=mumps&arch=hppa&ver=5.8.2-1&stamp=1777034697&raw=0
is

=== running c_example (serial) ===
Fatal error in internal_Allreduce: Invalid communicator, error stack:
internal_Allreduce(142): MPI_Allreduce(sendbuf=0xf947dfd0, recvbuf=0xf947dfc8, count=1, MPI_2INTEGER, MPI_MINLOC, comm=0x0) failed
internal_Allreduce(45).: Invalid communicator
[unset]: PMIU_write error; fd=-1 buf=:cmd=abort exitcode=67710469 message=abort
:
system msg for write_line failure : Bad file descriptor

so still referring to PMI via PMIU_write