fix: icalendar v6 compatibility

[dotlambda]

fixes #144

See https://github.com/collective/icalendar/blob/v6.0.0/CHANGES.rst for the changelog.

[5ila5]

Is there anyway this could be merged in the near future? Our HomeAssisntant integration relies on icalevents, but breaks if people install other integrations requiring the new calendar version.

See:
mampfes/hacs_waste_collection_schedule#2893

[peterbaumert]

@JamieMagee you know when this can be merged?

[BoGnY]

someone can merge this?!?!?!?!?

3 months waiting to merge a fix

[andreasbrett]

Is there anyway this could be merged in the near future? Our HomeAssisntant integration relies on icalevents, but breaks if people install other integrations requiring the new calendar version.

See: mampfes/hacs_waste_collection_schedule#2893

@5ila5
Since icalevents is such a tiny library and all ICS-related providers in Waste Collection Schedule are affected by these delays here: what do you think about packaging a fork (with this PR merged) into WCS? Just as a workaround that could be changed back to the original pypi icalevents once it works with icalendar 6.

[DerDreschner]

@5ila5 : What about limiting the compatible / installed version in the requirements.txt / manifest.json to

icalendar>=4.0.9,<=5.0.13
icalevents<=0.1.29

in the expectation that 0.1.30 / 0.2.x will be compatible with icalendar 6.x in the future? Or at least until there is a replacement for icalevents that is better maintained?

In my experience as professional software developer, using a fixed version (or at least max tested version as there are multiple HA/Python versions should be supported) is far less stressful then just installing the latest version on every build/installation without any tests. Sure, you have to track the dependencies and update them from time to time, but at least the project as a whole will not break one day totally unexpected due to an incompatible dependency update being published...

Edit: Ahh, nevermind. Dependency hell as everything is running in the same python environment and https://github.com/franc6/ics_calendar is using icalendar~=6.1.0 which makes the use of icalendar 5.0.13 impossible... Sorry for my post!

[DerDreschner]

@eigenmannmartin Maybe you can help us out by merging and creating a new release?