Add the std library for target
rustup target add armv7-unknown-linux-gnueabihf
Install cross compilation tools
apt install gcc-multilib-arm-linux-gnueabihf libc6-armhf-cross libc6-dev-armhf-cross
Update the .cargo/config to reflect the correct linker
#.cargo/config
[target.arm7-unknown-linux-gnueabifh]
linker = "arm-linux-gnueabihf-gcc"
Build the project for Pi
cargo build --target=armv7-unknown-linux-gnueabihf