Is there any reason why https://tracker.debian.org/pkg/gcc-12-cross-ports and https://tracker.debian.org/pkg/binutils can't be used to produce gcc-avr avr-libc & binutils-avr packages? Of course we still need to add a few dependencies (e.g. core-avr).
See the discussion in https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=932989 - a switch from the Atmel/Microchip toolchain to mainstream gcc was already up for discussion, but Ardö has mentioned that he lacks the time to do it.
There is no mention of AVR on the GCC 11 and 12 changelog: https://gcc.gnu.org/gcc-11/changes.html https://gcc.gnu.org/gcc-12/changes.htmlSo, I'm not sure if the announced deprecation of the AVR target has actually happened. As I understand, there's at least the Arduino community who has an active interest in keeping AVR support alive.
If you're up for it, please take a shot at upgrading the packages to the mainstream versions. I can't contribute a lot of time either, but I'd be happy to support you with bug fixing and testing.