Nightly rust cargo cross compile with openssl

gitlab-ci.yml

build-nightly:
  image: rustlang/rust:nightly
  before_script:
    - dpkg --add-architecture armhf
    - apt-get update && apt-get install --no-install-recommends -y gcc-arm-linux-gnueabihf libc6-armhf-cross libc6-dev-armhf-cross libssl-dev:armhf
    # Install OpenSSL
    - export CARGO_TARGET_ARMV7_UNKNOWN_LINUX_GNUEABIHF_LINKER=arm-linux-gnueabihf-gcc
    - export OPENSSL_INCLUDE_DIR=/usr/include/openssl/
    - export OPENSSL_LIB_DIR=/usr/lib/arm-linux-gnueabihf/
    # Rustup configuration
    - rustup target add armv7-unknown-linux-gnueabihf
    - rustup default nightly
    - rustc --version
  script:
    - cargo build --target=armv7-unknown-linux-gnueabihf --release