Add cross compilation test with crossenv

Author: messense

.github/workflows/ci.yml

@@ -169,3 +169,49 @@ jobs:
           pip install rust_with_cffi/dist/rust_with_cffi*.whl
           python -c "from rust_with_cffi import rust; assert rust.rust_func() == 14"
           python -c "from rust_with_cffi.cffi import lib; assert lib.cffi_func() == 15"
+
+  test-cross-compile:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        platform: [
+          { target: "aarch64-unknown-linux-gnu", arch: "aarch64" },
+          { target: "armv7-unknown-linux-gnueabihf", arch: "armv7" },
+        ]
+    steps:
+      - uses: actions/checkout@master
+      - name: Build Wheels
+        run: |
+          echo 'curl -sSf https://sh.rustup.rs | sh -s -- -y --default-toolchain stable
+          source ~/.cargo/env
+          rustup target add ${{ matrix.platform.target }}
+          cd examples/rust_with_cffi/
+          python3.6 -m pip install crossenv
+          python3.6 -m crossenv "/opt/python/cp36-cp36m/bin/python3" --cc $TARGET_CC --cxx $TARGET_CXX --sysroot $TARGET_SYSROOT --env LIBRARY_PATH= --manylinux manylinux1 venv
+          . venv/bin/activate
+          build-pip install cffi wheel
+          cross-expose cffi
+          pip install wheel
+          pip install -e ../../
+          unset CARGO_BUILD_TARGET
+          python setup.py bdist_wheel --py-limited-api=cp36
+          ls -la dist/
+          ' > build-wheels.sh
+
+          docker run --rm -v "$PWD":/io -w /io messense/manylinux2014-cross:${{ matrix.platform.arch }} bash build-wheels.sh
+      - name: Install abi3 wheel and run tests
+        uses: uraimo/run-on-arch-action@v2.0.5
+        with:
+          arch: ${{ matrix.platform.arch }}
+          distro: ubuntu20.04
+          dockerRunArgs: |
+            --volume "${PWD}/examples:/examples"
+          install: |
+            apt-get update
+            apt-get install -y --no-install-recommends python3 python3-dev python3-pip build-essential libffi-dev
+          run: |
+            cd /examples
+            python3 --version
+            pip3 install rust_with_cffi/dist/rust_with_cffi*.whl
+            python3 -c "from rust_with_cffi import rust; assert rust.rust_func() == 14"
+            python3 -c "from rust_with_cffi.cffi import lib; assert lib.cffi_func() == 15"