Replace pretty-cron dependency with cron_descriptor

[pluehne]

I just realized that pretty_cron is used in a few places in this project but the authors of pretty_cron state that it is no longer maintained:

Retired in favour of cron_descriptor.

This project is no longer maintained.

It might make sense to follow the original authors’ recommendation to switch to cron_descriptor instead. Consider this just as a heads-up 🙂.

[rytilahti]

Thanks for reporting this Patrick! pretty_cron is used only in one place (converting cron format to printable format) in mirobo cli tool, however, I don't think the timer functionality is used that much here. The conversion seems to be straightforward though, so I suppose we can either make the change or simply drop the dependency altogether.

[pluehne]

@rytilahti: That sounds good! I may be able to help with replacing or dropping the dependency, but I’ll be pretty busy until the end of the year.

[rytilahti]

Ok, this is definitely a low priority, and I think changing the dependency should be combined with making the timer functionality more straightforward to use (currently you need to construct your cron string, make sure everything is fine related to the active timezone etc. to use it). But if you want to tackle this, please feel free to do so :-)

[pluehne]

I’ll see what I can do. But if you have concrete plans to improve the timer interface, feel free to go ahead and don’t wait for me 🙂!

[rytilahti]

As I'm not personally using it at all (preferring to handle scheduling via other means), so it's not of importance to me, and as is, it's just there for completeness. Therefore I'm wondering if the dependency should be dropped altogether, but I have really no plans on this for a way or another.

[frostworx]

looks like this is already fixed. the only occurence of "pretty_cron" is in requirements.txt