Add linux aarch64 wheel build support

.github/workflows/build.yml

@@ -4,12 +4,16 @@ on: push
 
 jobs:
   build_wheels:
-    name: Build wheels on ${{ matrix.os }}
+    name: Build wheels on ${{matrix.arch}} for ${{ matrix.os }}
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
         # os: [ubuntu-18.04, windows-latest, macos-latest] # skip windows 
         os: [ubuntu-20.04, macos-11]
+        arch: [auto, aarch64]
+        exclude:
+         - os: macos-11
+           arch: aarch64
 
     steps:
       - uses: actions/checkout@v2
@@ -23,15 +27,23 @@ jobs:
         with:
           python-version: '3.7'
 
+      #cibuildwheel support aarch64, via emulation.
+      #Please refer - https://cibuildwheel.readthedocs.io/en/stable/faq/#emulation
+      - uses: docker/setup-qemu-action@v1
+        if: ${{ matrix.arch == 'aarch64' }}
+        name: Set up QEMU
+
       - name: Install cibuildwheel
         run: |
           python -m pip install cibuildwheel==2.1.1
 
       - name: Build wheels
         env:
+          CIBW_ARCHS_LINUX: ${{matrix.arch}}
           CIBW_SKIP: "pp* *-manylinux_i686"
           CIBW_BEFORE_BUILD_LINUX: "/bin/bash cibuild/linux_steps.sh"
           CIBW_BEFORE_BUILD_MACOS: "/bin/bash cibuild/macos_steps.sh"
+          CIBW_BEFORE_TEST_LINUX: "/bin/bash cibuild/aarch64_extra_steps.sh"
           CIBW_TEST_COMMAND: "cd {project}/pyosmium && rm -rf build && pytest test"
           CIBW_TEST_REQUIRES: pytest shapely
           CIBW_TEST_SKIP: "cp310-macosx*" # missing libgeos

cibuild/aarch64_extra_steps.sh

@@ -0,0 +1,9 @@
+#!/bin/sh
+
+if [ "$(uname -m)" == "aarch64" ]
+then
+    yum install -y wget
+    wget https://download-ib01.fedoraproject.org/pub/epel/7/aarch64/Packages/g/geos-3.4.2-2.el7.aarch64.rpm
+    rpm -i geos-3.4.2-2.el7.aarch64.rpm
+    rm geos-3.4.2-2.el7.aarch64.rpm
+fi

cibuild/linux_steps.sh

@@ -6,6 +6,7 @@ echo "Running Linux steps"
 
 CMAKE_BIN_URL_64=https://cmake.org/files/v3.6/cmake-3.6.3-Linux-x86_64.sh
 CMAKE_BIN_URL_32=https://cmake.org/files/v3.6/cmake-3.6.3-Linux-i386.sh
+CMAKE_BIN_URL_aarch64=https://cmake.org/files/v3.21/cmake-3.21.0-linux-aarch64.sh
 
 function build_boost {
     mkdir -p boost
@@ -27,6 +28,8 @@ function build_boost {
 function build_cmake {
     if [ "x${AUDITWHEEL_ARCH}" == "xi686" ] ; then
         curl -o /tmp/cmake.sh "${CMAKE_BIN_URL_32}"
+    elif [ "x${AUDITWHEEL_ARCH}" == "xaarch64" ] ; then
+        curl -o /tmp/cmake.sh "${CMAKE_BIN_URL_aarch64}"
     else
         curl -o /tmp/cmake.sh "${CMAKE_BIN_URL_64}"
     fi
@@ -51,9 +54,7 @@ ln -sf $(pwd)/pybind11 pyosmium/contrib/pybind11
 ln -sf $(pwd)/libosmium pyosmium/contrib/libosmium
 ln -sf $(pwd)/protozero pyosmium/contrib/protozero
 
-
-yum install -y sparsehash-devel expat-devel boost-devel zlib-devel
-
+yum install -y expat-devel boost-devel zlib-devel
 
 # install bzip2
 build_new_zlib