Yes, that is correct, I've read the gitlab entries yesterday. But if you read them you will find that this is basically a stalemate [gnome calendar does not support ics files and therefore cannot have the mime but mime is required to select it on the settings panel] and the problem still persist - means - despite the fact that you have installed appropriate software (gnome-calendar) you cannot use it (in terms of integration). Therefore I thought that it would be more benefitial for the OP if I'd give a (agreed, hacky) way of OP being able to select the calendar app rather than leaving the bug without resolution.
regards, -- pozdrawiam serdecznie, Mateusz Mikołajczyk, a.k.a. toudi
