I may have sent an email to the old list (I don't know!); I'll try to repeat it here:

I noticed that the calf plugins work but without UI. While trying to investigate, I found this issue:

https://gitlab.archlinux.org/archlinux/packaging/packages/calf/-/issues/3
Does this only affect Arch Linux because it is removing GTK2, or could it be a more general problem?