Support for FIDO keys on slackware-current (pre- 15, post json-c 0.15 update libu2f-host will not compile)

libu2f-host does not compile on -current since the upgrade to json-c 0.15 . master will build, and applying a patch from "Add support for upcoming json-c 0.14.0" fixes the problem, but the libu2f-host project is archived, so I suppose no more releases. It looks like it has been superseded by libfido2. OTOH, udev/systemd have pulled in FIDO support directly but I don't see anything like that in eudev.

So I guess I'm wondering if anyone has tried libfido2 or has a slackbuild for it I could try out, since I don't imagine the eudev maintainers have any interest in pulling in fido2 support from systemd.