Invalid argument: '--notebook-dir=..'

JupyterHub
1

Hi,
I’m using DockerSpawner and I have the settings

notebook_dir = os.environ.get('DOCKER_NOTEBOOK_DIR') or '/home/jovyan/work'
c.DockerSpawner.notebook_dir = notebook_dir
c.DockerSpawner.volumes = { 'jupyterhub-user-{username}': notebook_dir }

However, when the docker container is spawned, I get the error.

[W 2020-01-27 16:58:55.437 JupyterHub loader:664] Unrecognized alias: '--notebook-dir=/home/jovyan/work', it will probably have no effect.
[C 2020-01-27 16:58:55.465 JupyterHub application:90] Bad config encountered during initialization:
[C 2020-01-27 16:58:55.466 JupyterHub application:91] Invalid argument: '--notebook-dir=/home/jovyan/work'

Appreciate any help