[ Ref. git.devuan.org/jaretcantu/eudev/issues/2 ]
Hello Jaret,
since I cannot comment on git.devuan.org I'll try here instead.
I believe udev is complaining about the missing hwdb.bin file,
because it is not present in the _initramfs_. Thus, a simple
udevadm hwdb --update won't suffice, you'd also have to put it
in the initramfs to silence udev.
A tiny little bit of research indicates that this "error" can
presumably safely be ignored, since it was likely meant to be
more of a debug message.
Regards,
Urban