MarsSeed [1] filed a deletion request for esphomeyaml-dev [2]: Submitted on 2022-06-26 and never updated. Not useful to keep as is. The stable AUR/esphome is much newer: updated two weeks ago as of this writing.
[1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/esphomeyaml-dev/
