Fail properly when external folder is not available to north container
When a docker container is created and the folder is not properly accessible the jupyterhub fails with Only the nomad-service can launch specialized tools
which is confusing. It should be checking the rights of the folder before spawning and throw an appropriate error or don't mount the external folder at all (maybe a config setting for a fail switch?).
Here is the external folder mounting part: https://gitlab.mpcdf.mpg.de/nomad-lab/nomad-FAIR/-/blob/develop/nomad/jupyterhub_config.py?ref_type=heads#L58