Run pip under correct arch in macOS CI

Author: topolarity

.github/workflows/system.yml

@@ -15,14 +15,29 @@ jobs:
       matrix:
         os:
           - ubuntu-latest
-          - macos-latest
           - windows-latest
         architecture: [x64]
         python-version: ['3.x']
         julia-version:
           - '1'
           - 'nightly'
         include:
+          - os: macos-latest
+            architecture: arm64
+            python-version: '3.x'
+            julia-version: '1'
+          - os: macos-latest
+            architecture: arm64
+            python-version: '3.x'
+            julia-version: 'nightly'
+          - os: macos-latest
+            architecture: x64 # agent is arm64 (runs under Rosetta)
+            python-version: '3.x'
+            julia-version: '1'
+          - os: macos-latest
+            architecture: x64 # agent is arm64 (runs under Rosetta)
+            python-version: '3.x'
+            julia-version: 'nightly'
           # 32 bit Windows:
           - os: windows-latest
             architecture: x86
@@ -53,8 +68,18 @@ jobs:
         with:
           python-version: ${{ matrix.python-version }}
           architecture: ${{ matrix.architecture }}
-      - run: python -m pip install --user numpy
-      - run: python -m pip install virtualenv
+      - name: Install numpy
+        run: python -m pip install --user numpy
+        if: ${{ !(matrix.os == 'macos-latest' && matrix.architecture == 'x64') }}
+      - name: Install numpy (Rosetta)
+        run: arch -x86_64 python -m pip install --user numpy
+        if: ${{ matrix.os == 'macos-latest' && matrix.architecture == 'x64' }}
+      - name: Install virtualenv
+        run: python -m pip install virtualenv
+        if: ${{ !(matrix.os == 'macos-latest' && matrix.architecture == 'x64') }}
+      - name: Install virtualenv (Rosetta)
+        run: arch -x86_64 python -m pip install virtualenv
+        if: ${{ matrix.os == 'macos-latest' && matrix.architecture == 'x64' }}
       - run: virtualenv --version
       - name: Setup julia
         uses: julia-actions/setup-julia@v1