MarsSeed [1] filed a deletion request for avr-libc-atmel [2]: Abandoned, broken variant/duplicate pkg from 2017 of extra repo's avr- gcc. Sources unavailable (could not resolve host). Upstream Atmel has been merged with Microchip; the original Atmel servers got shut down, and Microchip has put all their avr-gcc distribution files behind a loginwall. [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/avr-libc-atmel/