MarsSeed [1] filed a deletion request for linux-aarch64-rock64-bin [2]: Orphan kernel variant from 2018-08-14, one-time effort. Not useful to keep.
[1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/linux-aarch64-rock64-bin/
