FAQ
BUGS & SOLUTIONS
Error with submission script
Error no display name and no $DISPLAY
with python scripts that use matplotlib:
While running a python script that use Matplotlib and try to save a figure on a server it is mandatory to use a non-GUI backend for Matplotlib even just to save the figure. Indeed, an error or a warning can been raised or simply the output file will not be created but the script will end successfuly.
Error: no display name and no $DISPLAY environment variable.
The solution is to add those lines at the top of the python script
import matplotlib matplotlib.use("Agg")A userwarning will be raised
/home/user1/works/venv/local/lib/python2.7/site-packages/matplotlib/figure.py:457: UserWarning: matplotlib is currently using a non-GUI backend, so cannot show the figure "matplotlib is currently using a non-GUI backend, "
Error Terminus’s daemonization
Error -A option unrecognized
with Celery daemonization:
> journalctl -xe
Error: no such option: -A
oct. 28 15:24:12 Workstation sh[23120]: celery multi v5.0.0 (singularity)
oct. 28 15:24:12 Workstation sh[23120]: > Starting nodes...
oct. 28 15:24:12 Workstation sh[23120]: > celery1@workstation: * Child terminated with exit code 2
oct. 28 15:24:12 Workstation sh[23120]: FAILED
oct. 28 15:24:12 Workstation sh[23144]: > celery1@workstation: DOWN
oct. 28 15:24:27 Workstation sh[23222]: Usage: __main__.py worker [OPTIONS]
oct. 28 15:24:27 Workstation sh[23222]: Try '__main__.py worker --help' for help.
oct. 28 15:24:27 Workstation sh[23222]: Error: no such option: -A
This is a reported error in Celery 5.0.0, that has been fixed `Celery_issue_6363`_. Upgrade the celery to 5.0.1 fix that issue.