I think the first thing to figure out would be why udev is getting shut down. Perhaps you could extract its logs? journalctl -b -u systemd-udevd.service
should do the trick. This gets you the logs of the current boot’s udevd service.
Once you know why it is shutting down, it will be time to figure out how to stop it from shutting down. That should, hopefully, fix the problem you’re having.
Mason and CMake are the two major players I’ve seen along autotools. Are they better? In some respects, yes (especially Mason, imo), in others… not really. For a pet project that only targets two platforms, I’d just stick to handwritten worst-practices Makefile. You will likely have less trouble with that than any of the others, simply because you know it already.