Crash when using serial IO and MPI

Doing a simple build of SWIFT at b2efc6e3:

./configure --with-metis

and running the EAGLE_6/.1 example:

mpirun -np 4 ../../swift_mpi --hydro --threads=2 -n 8 eagle_6.yml -v 1

we crash with:

[0000] [00015.6] write_output_serial: Snapshot and internal units match. No conversion needed.
HDF5-DIAG: Error detected in HDF5 (1.10.0-patch1) thread 23132795066560:
  #000: ../../../src/H5L.c line 480 in H5Lcreate_soft(): not a location
    major: Invalid arguments to routine
    minor: Inappropriate type
  #001: ../../../src/H5Gloc.c line 195 in H5G_loc(): invalid group ID
    major: Invalid arguments to routine
    minor: Bad value
[0000] [00015.6] serial_io.c:write_output_serial():1158: Error while creating alias for particle group.

Quick bisection suggests this happened with !1047 (merged).