Ha, thanks! This answers many of my questions. To be honest, using an overlay and custom ebuild is more involved than I wanted to go, specially knowing that I will be stuck with an older crossdev anyway. Before going that route, I will try using a Gentoo docker image dedicated to distcc and / or usermode QEMU chroot env (https://github.com/sakaki-/gentoo-on-rpi3-64bit/wiki/Build-aarch64-Packages-on-your-PC%2C-with-User-Mode-QEMU-and-binfmt_misc ). I will report my findings here so that if others follow the same route they can benefit from our shared experience.
I'm trying to setup crossdev for Aarch64 Raspberry Pi3 cross-compilation on my x64 Funtoo PC as described here. While crossdev itself emerged ok, entering sudo crossdev --stable -t aarch64-unknown-linux-gnu fails after a few seconds with a rather laconic * error: binutils failed :( I looked into filing a bug, as it seems this should be stable now, the closest entry dating back from 2015 but I wanted to check first if anybody had this working currently. I've attached the files I have, as recommended by the full command output: * crossdev version: 20180410 * H