Add support for building MacOS wheels in cibuildwheel

.github/scripts/python_wheels/cibw_before_all.sh

@@ -15,16 +15,46 @@ export PYTHON="python${PYTHON_VERSION}"
 if [ "$(uname)" == "Linux" ]; then
     # manylinux2014 is based on CentOS 7, so use yum to install dependencies
     yum install -y wget doxygen
+elif [ "$(uname)" == "Darwin" ]; then
+    brew install cmake doxygen
+
+    # If MACOSX_DEPLOYMENT_TARGET is not explicitly set, default to the version of the host system.
+    if [[ -z "${MACOSX_DEPLOYMENT_TARGET}" ]]; then
+        export MACOSX_DEPLOYMENT_TARGET="$(sw_vers -productVersion | cut -d '.' -f 1-2)"
+    fi
+fi
+
+# Install Boost from source
+wget https://archives.boost.io/release/1.87.0/source/boost_1_87_0.tar.gz --quiet
+tar -xzf boost_1_87_0.tar.gz
+cd boost_1_87_0
+
+BOOST_PREFIX="$HOME/opt/boost"
+./bootstrap.sh --prefix=${BOOST_PREFIX}
 
-    # Install Boost from source
-    wget https://archives.boost.io/release/1.87.0/source/boost_1_87_0.tar.gz --quiet
-    tar -xzf boost_1_87_0.tar.gz
-    cd boost_1_87_0
-    ./bootstrap.sh --prefix=/opt/boost
-    ./b2 install --prefix=/opt/boost --with=all -d0 
-    cd ..
+if [ "$(uname)" == "Linux" ]; then
+    ./b2 install --prefix=${BOOST_PREFIX} --with=all -d0
 elif [ "$(uname)" == "Darwin" ]; then
-    brew install wget cmake boost doxygen
+    ./b2 install --prefix=${BOOST_PREFIX} --with=all -d0 \
+        cxxflags="-mmacosx-version-min=${MACOSX_DEPLOYMENT_TARGET}" \
+        linkflags="-mmacosx-version-min=${MACOSX_DEPLOYMENT_TARGET}"
+fi
+cd ..
+
+# Export paths so CMake or build system can find Boost
+export BOOST_ROOT="${BOOST_PREFIX}"
+export BOOST_INCLUDEDIR="${BOOST_PREFIX}/include"
+export BOOST_LIBRARYDIR="${BOOST_PREFIX}/lib"
+
+# Ensure runtime linker can find Boost libraries
+export LD_LIBRARY_PATH="${BOOST_LIBRARYDIR}:$LD_LIBRARY_PATH" # For Linux
+export REPAIR_LIBRARY_PATH="${BOOST_LIBRARYDIR}:$DYLD_LIBRARY_PATH" # For macOS, REPAIR_LIBRARY_PATH is used by delocate
+
+if [ "$(uname)" == "Darwin" ]; then
+    # Explicitly add rpath to Boost dylibs so delocate can find them
+    for dylib in ${BOOST_LIBRARYDIR}/*.dylib; do
+        install_name_tool -add_rpath "@loader_path" "$dylib"
+    done
 fi
 
 $(which $PYTHON) -m pip install -r $PROJECT_DIR/python/dev_requirements.txt

.github/workflows/build-cibw.yml

@@ -76,22 +76,22 @@ jobs:
             manylinux_image: manylinux2014
 
           # MacOS x86_64
-          # - os: macos-13
-          #   python_version: "3.10"
-          #   cibw_python_version: 310
-          #   platform_id: macosx_x86_64
-          # - os: macos-13
-          #   python_version: "3.11"
-          #   cibw_python_version: 311
-          #   platform_id: macosx_x86_64
-          # - os: macos-13
-          #   python_version: "3.12"
-          #   cibw_python_version: 312
-          #   platform_id: macosx_x86_64
-          # - os: macos-13
-          #   python_version: "3.13"
-          #   cibw_python_version: 313
-          #   platform_id: macosx_x86_64
+          - os: macos-13
+            python_version: "3.10"
+            cibw_python_version: 310
+            platform_id: macosx_x86_64
+          - os: macos-13
+            python_version: "3.11"
+            cibw_python_version: 311
+            platform_id: macosx_x86_64
+          - os: macos-13
+            python_version: "3.12"
+            cibw_python_version: 312
+            platform_id: macosx_x86_64
+          - os: macos-13
+            python_version: "3.13"
+            cibw_python_version: 313
+            platform_id: macosx_x86_64
 
     steps:
       - name: Checkout
@@ -130,6 +130,14 @@ jobs:
         run: |
           cmake . -B build -DGTSAM_BUILD_PYTHON=1 -DGTSAM_PYTHON_VERSION=${{ matrix.python_version }}
 
+      # If on macOS, we previously installed boost using homebrew for the first build.
+      # We need to uninstall it before building the wheels with cibuildwheel, which will
+      # install boost from source.
+      - name: Uninstall Boost (MacOS)
+        if: runner.os == 'macOS'
+        run: |
+          brew uninstall boost
+
       - name: Build and test wheels
         env:
           # Generate the platform identifier. See https://cibuildwheel.pypa.io/en/stable/options/#build-skip.
@@ -139,6 +147,13 @@ jobs:
           CIBW_ARCHS: all
           CIBW_ENVIRONMENT_PASS_LINUX: DEVELOP TIMESTAMP
 
+          # Set the minimum required MacOS version for the wheels.
+          MACOSX_DEPLOYMENT_TARGET: 10.15
+
+          # Set DYLD_LIBRARY_PATH to REPAIR_LIBRARY_PATH, which is set in cibw_before_all.sh. REPAIR_LIBRARY_PATH
+          # simply appends BOOST_LIBRARYDIR to the path, which is required during during link-time repair.
+          CIBW_REPAIR_WHEEL_COMMAND_MACOS: DYLD_LIBRARY_PATH=$REPAIR_LIBRARY_PATH delocate-wheel --require-archs {delocate_archs} -w {dest_dir} -v {wheel}
+
           # Use build instead of pip wheel to build the wheels. This is recommended by PyPA.
           # See https://cibuildwheel.pypa.io/en/stable/options/#build-frontend.
           CIBW_BUILD_FRONTEND: "build"