Bug#1145118: adios4dolfinx: FTBFS: E ValueError: [Sat Aug 22 10:11:38 2026] [ADIOS2 EXCEPTION] <Core> <IOHDF5> <MakeEngineHDF5> : A serial HDF5 engine cannot be used with a communicator that is MPI-based.

[Drew Parsons]

Source: adios4dolfinx
Followup-For: Bug #1145118
Control: tags -1 ftbfs

This error makes no sense.  It's saying that adios2 is using serial
HDF5, when MPI parallel HDF5 is needed.  That bit makes sense.
What does not make sense is that it is
adios2.bindings.adios2_bindings_mpi.ADIOS reporting this error,
i.e. the MPI build is saying it's using the serial engine.

Looks like something's gone wrong in adios2.
Perhaps they're not properly updated for HDF5 v2.