https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111639
--- Comment #4 from Georg-Johann Lay <gjl at gcc dot gnu.org> --- (In reply to Jonathan Wakely from comment #3) > Which versions of avr-libc are supported with gcc? The versions are only very loosely coupled. Anything from AVR-LibC v1.8 on (or maybe even older) should be fine with avr-gcc v5+.
