debootstrap trusty /build-armhf
# Will need to do it after every reboot
mount --rbind /proc /build-armhf/proc
mount --rbind /home /build/armhf/home
chroot /build-armhf
adduser YOUR_USER_NAME_HERE
Change /etc/apt/sources.list
to:
deb [arch=amd64,i386] http://archive.ubuntu.com/ubuntu trusty main restricted universe multiverse
deb [arch=amd64,i386] http://security.ubuntu.com/ubuntu trusty-security main restricted universe multiverse
deb [arch=armhf] http://ports.ubuntu.com/ubuntu-ports trusty main
dpkg --add-architecture armhf
apt-get update
apt-get install clang-3.9 libfontconfig1-dev:armhf python-minimal