If you are reading this post it’s probably that you already checked other resources and had some problem to build  avr-g++ using crossdev utility.

crossdev -t avr -s4

Note that cpp compiler wasn’t created.

# qlist cross-avr/gcc | grep bin
/usr/i686-pc-linux-gnu/avr/gcc-bin/4.4.1/avr-gccbug
/usr/i686-pc-linux-gnu/avr/gcc-bin/4.4.1/avr-gcov
/usr/i686-pc-linux-gnu/avr/gcc-bin/4.4.1/avr-cpp
/usr/i686-pc-linux-gnu/avr/gcc-bin/4.4.1/avr-gcc
/usr/i686-pc-linux-gnu/avr/gcc-bin/4.4.1/avr-gcc-4.4.1

The problem is easy to fix. Simple edit /etc/portage/package.use/cross-avr changing ‘nocxx‘ to ‘-nocxx‘ and run emerge again.

emerge cross-avr/gcc cross-avr/avr-libc dev-embedded/avrdude

I’m using AVR toolchain with Arduino 0017 flashing by USB.