Make sure the cross compiler is in the path, needed for some libs like log4rs
export PATH=$PATH:/home/user/cc/gcc-linaro-7.3.1-2018.05-x86_64_arm-linux-gnueabihf/bin/
export PATH=$PATH:/home/ed/cc/tools/arm-bcm2708/arm-linux-gnueabihf/bin/rustup override set nightly