Handling of missing files in OBS_YAML

[AndrewEichmann-NOAA]

Currently when loading OBS_YAML with wxflow.YAMLFile, if a line in OBS_YAML such as

- !INC ${OBS_YAML_DIR}/insitu_profile_bathy.yaml

points to a non-existant file, the script fails with the following error:

FileNotFoundError: [Errno 2] No such file or directory: '/scratch1/NCEPDEV/da/Andrew.Eichmann/fv3gfs/insitu/global-workflow/sorc/gdas.cd/parm/soca/obs/config/insitu_profile_bathy.yaml

This could be caught, but it is unclear how to handle the exception while using the rest of the possibly existing files in OBS_YAML.

• Can we format OBS_YAML to not use the INC directive and just access the list of files, and load those individually?
• Should some exception handling be requested for wxflow.YAMLFile?
• Or do we want to preserve this level of brittleness?

[guillaumevernieres]

@AndrewEichmann-NOAA , what we have now is the correct behavior. It should fail if we're trying to assimilate an obs type that we don't know yet how to assimilate (indicated by the absence of a yaml file).