Use clang if on MacOS

Author: yambati03

.github/scripts/python_wheels/cibw_before_all.sh

@@ -24,7 +24,8 @@ if [ "$(uname)" == "Linux" ]; then
     ./b2 install --prefix=/opt/boost --with=all 
     cd ..
 elif [ "$(uname)" == "Darwin" ]; then
-    brew install wget cmake boost
+    brew install wget cmake ninja boost
+    sudo xcode-select -switch /Applications/Xcode.app
 fi
 
 $(which $PYTHON) -m pip install -r $PROJECT_DIR/python/dev_requirements.txt

.github/workflows/build-cibw.yml

@@ -109,6 +109,12 @@ jobs:
           echo "DEVELOP=1" >> $GITHUB_ENV
           echo "TIMESTAMP=${{ needs.get_system_time.outputs.timestamp }}" >> $GITHUB_ENV
 
+      - name: Set compiler to clang if on MacOS
+        if: startsWith(matrix.os, 'macos')
+        run: |
+          echo "CC=clang" >> $GITHUB_ENV
+          echo "CXX=clang++" >> $GITHUB_ENV
+
       - name: Install Dependencies
         run: |
           python3 -m pip install -r python/dev_requirements.txt