Edited process for creating output directories to avoid race condition

[dominicanstey]

Changed the process for making output directories to a 'try/except', to avoid the race condition created by the 'if not' process

[williamjameshandley]

Hi @dominicanstey

Unfortunately the tests are showing that whilst this fixes the race condition for the MPI case, it breaks for the non-mpi case.

Do you need the conditional statement now? Couldn't you just run os.makedirs on all cores regardless of rank in this setup?

You should also specify that you're catching the OSError exception, rather than a generic one.

[williamjameshandley]

@dominicanstey any update on the above?