Add cross compilation test in CI

.github/workflows/ci.yml

@@ -183,6 +183,16 @@ jobs:
         env:
           TOX_TESTENV_PASSENV: "CARGO_BUILD_TARGET"
 
+      - name: Test cross compilation
+        if: ${{ matrix.platform.os == 'ubuntu-latest' && matrix.python-version == '3.9' }}
+        uses: messense/maturin-action@v1
+        env:
+          PYO3_CROSS_LIB_DIR: /opt/python/cp39-cp39/lib
+        with:
+          target: aarch64-unknown-linux-gnu
+          manylinux: auto
+          args: --release -i python3.9 --no-sdist -m examples/maturin-starter/Cargo.toml
+
     env:
       CARGO_TERM_VERBOSE: true
       CARGO_BUILD_TARGET: ${{ matrix.platform.rust-target }}