MarsSeed [1] filed a deletion request for eudev [2]: This package has already been deleted once.
It is no longer compatible with Arch Linux, only with some of the completely greenfield-reconfigured, ground-up rebuilt systemd-less Arch Linux spinoffs. (Maybe back in 2015, it was viable to manually replace systemd on an installed Arch setup with a legacy init system, but it is not possible today.) [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/eudev/