From a26751327d3212690b46d0cc1e2c7dd7e2a86df9 Mon Sep 17 00:00:00 2001
From: Thomas A Caswell <tcaswell@gmail.com>
Date: Tue, 9 Mar 2021 20:27:12 -0500
Subject: [PATCH] Backport PR #19402: Build aarch64 wheels

---
 .github/workflows/cibuildwheel.yml | 45 ++++++++++++++++++++++++++----
 1 file changed, 39 insertions(+), 6 deletions(-)

diff --git a/.github/workflows/cibuildwheel.yml b/.github/workflows/cibuildwheel.yml
index ac542bf2ab77..2100d15fe000 100644
--- a/.github/workflows/cibuildwheel.yml
+++ b/.github/workflows/cibuildwheel.yml
@@ -12,11 +12,24 @@ jobs:
   build_wheels:
     name: Build wheels on ${{ matrix.os }}
     runs-on: ${{ matrix.os }}
+    env:
+      min-numpy-version: "1.16.0"
+      min-numpy-hash: "04/b6/d7faa70a3e3eac39f943cc6a6a64ce378259677de516bd899dd9eb8f9b32"
     strategy:
       matrix:
         os: [ubuntu-18.04, windows-latest, macos-latest]
+        cibw_archs: ["auto"]
+        include:
+          - os: ubuntu-18.04
+            cibw_archs: "aarch64"
 
     steps:
+      - name: Set up QEMU
+        if: matrix.cibw_archs == 'aarch64'
+        uses: docker/setup-qemu-action@v1
+        with:
+          platforms: arm64
+
       - uses: actions/checkout@v2
         with:
           fetch-depth: 0
@@ -26,9 +39,26 @@ jobs:
         with:
           python-version: '3.7'
 
+      - uses: actions/cache@v2
+        id: numpy-cache
+        with:
+          path: numpy-aarch64-cache/
+          key: numpy-${{ matrix.cibw_archs }}-cache-${{ env.min-numpy-version }}
+
       - name: Install cibuildwheel
         run: |
-          python -m pip install cibuildwheel==1.6.3
+          python -m pip install cibuildwheel==1.9.0
+
+      - name: Build minimum NumPy for aarch64
+        if: matrix.cibw_archs == 'aarch64' && steps.numpy-cache.outputs.cache-hit != 'true'
+        run: |
+          wget https://files.pythonhosted.org/packages/${{ env.min-numpy-hash }}/numpy-${{ env.min-numpy-version }}.zip
+          unzip numpy-${{ env.min-numpy-version }}.zip
+          cd numpy-${{ env.min-numpy-version }}
+          python -m cibuildwheel --output-dir ../numpy-aarch64-cache
+        env:
+          CIBW_BUILD: "cp36-* cp37-* cp38-*"
+          CIBW_ARCHS: aarch64
 
       - name: Copy setup.cfg to configure wheel
         run: |
@@ -43,17 +73,18 @@ jobs:
           CIBW_MANYLINUX_I686_IMAGE: manylinux1
           CIBW_BEFORE_BUILD: pip install certifi numpy==1.19.3
           MPL_DISABLE_FH4: "yes"
+          CIBW_ARCHS: ${{ matrix.cibw_archs }}
 
       - name: Build wheels for CPython
         run: |
           python -m cibuildwheel --output-dir dist
         env:
-          CIBW_BUILD: "cp3?-*"
-          CIBW_SKIP: "cp35-* cp36-* cp39-*"
+          CIBW_BUILD: "cp37-* cp38-*"
           CIBW_MANYLINUX_X86_64_IMAGE: manylinux1
           CIBW_MANYLINUX_I686_IMAGE: manylinux1
-          CIBW_BEFORE_BUILD: pip install certifi numpy==1.16
+          CIBW_BEFORE_BUILD: pip install certifi; pip install --find-links=numpy-aarch64-cache/ numpy==${{ env.min-numpy-version }}
           MPL_DISABLE_FH4: "yes"
+          CIBW_ARCHS: ${{ matrix.cibw_archs }}
 
       - name: Build wheels for CPython 3.6
         run: |
@@ -62,8 +93,9 @@ jobs:
           CIBW_BUILD: "cp36-*"
           CIBW_MANYLINUX_X86_64_IMAGE: manylinux1
           CIBW_MANYLINUX_I686_IMAGE: manylinux1
-          CIBW_BEFORE_BUILD: pip install certifi numpy==1.16
+          CIBW_BEFORE_BUILD: pip install certifi; pip install --find-links=numpy-aarch64-cache/ numpy==${{ env.min-numpy-version }}
           MPL_DISABLE_FH4: "yes"
+          CIBW_ARCHS: ${{ matrix.cibw_archs }}
         if: >
           startsWith(github.ref, 'refs/heads/v3.3') ||
           startsWith(github.ref, 'refs/tags/v3.3')
@@ -73,7 +105,8 @@ jobs:
           python -m cibuildwheel --output-dir dist
         env:
           CIBW_BUILD: "pp3?-*"
-          CIBW_BEFORE_BUILD: pip install certifi numpy==1.16
+          CIBW_BEFORE_BUILD: pip install certifi numpy==${{ env.min-numpy-version }}
+          CIBW_ARCHS: ${{ matrix.cibw_archs }}
         if: >
           runner.os != 'Windows' && (
           startsWith(github.ref, 'refs/heads/v3.3') ||