mpi-cmd-template: It is necessary to escape nr_ranks and cmd inside configuration file

[robert-mijakovic]

I tried to use mpi-cmd-template inside a configuration file but it fails because nr_ranks and cmd need to be escaped.
--mpi-cmd-template="srun -n %(nr_ranks)s %(cmd)s" results in:
ERROR: Failed to parse configuration options: Bad value substitution: option 'mpi-cmd-template' in section 'override' contains an interpolation key 'nr_ranks' which is not a valid option name. Raw value: '"srun -n %(cmd)s %(nr_ranks)s"'
However, specifying it with: --mpi-cmd-template="srun -n %%(nr_ranks)s %%(cmd)s" works fine.

[ocaisa]

This is a little bit misleading because --mpi-cmd-template="srun -n %(nr_ranks)s %(cmd)s" as a command line option is indeed correct. The issue arises if you try to put this in a configuration file, in that case you will need to escape the % with another %

[robert-mijakovic]

Correct, that is what I did and it worked.

[robert-mijakovic]

It is necessary to make it more clear in the documentation.