Avoid crash when can not get human readable description

[nijel]

Catch errors from cron-descriptor and display crontab as it is. Apparently there are crontabs which work in Celery, but cron-descriptor fails to format them.

Issue #647

[auvipy]

@Salamek can you have a look please?

[Salamek]

@auvipy It is ok as a hotfix (to prevent a crash)... but i think you should create a valid CRON expression from crontab object and pass it to cron_descriptor to get correctly displayed...

[auvipy]

but i think you should create a valid CRON expression from crontab object and pass it to cron_descriptor to get correctly displayed...

is celery doing this ? or this package need update as well?

[Salamek]

@auvipy looking on the src, looks like this package attempts to build a CRON expression from celery.schedules.crontab object (or its values saved in database) and fails doing so when non standard values are used when constructing celery.schedules.crontab (like full name days or months are not supported in valid CRON expression, but celery.schedules.crontab accepts and uses them anyway) so someone should create def celery_crontab_to_cron(celery.schedules.crontab: celery_crontab) -> str: function that returns normalized valid CRON from celery.schedules.crontab and passes it into cron_descriptor ;-)

[schinckel]

For what it's worth, I was getting this error in the admin.

I was able to resolve it without new code by updating the crontab data to change wednesday to wed (for example).

[auvipy]

For what it's worth, I was getting this error in the admin.

I was able to resolve it without new code by updating the crontab data to change wednesday to wed (for example).

should we mention this somewhere n docs?