Following up, h5py 2.10.0-7 now checks env var H5PY_ALWAYS_USE_MPI and
uses mpi if it is set.
That leaves 3 options for bitshuffle:
1) run always with mpirun (this is what Gilles did with the tests in his
nmu)
2) patch bitshuffle to
import h5py._debian_h5py_mpi as h5py
3) set H5PY_ALWAYS_USE_MPI in the environment (H5PY_ALWAYS_USE_MPI=1)
Option 2 will probably need the least action by users (i.e. their script
will then run in serial without mpirun).
A fourth option is to provide both serial and mpi builds of bitshuffle,
similar to h5py.
Drew
