MarsSeed [1] filed a deletion request for avr-libc-atmel-atmega328pb [2]: Unused package from 2017. Broken due to depending on the defunct avr-libc-atmel (see deletion request for the latter: PRQ#49880).
[1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/avr-libc-atmel-atmega328pb/
