Build linux/aarch64 wheels by compiling VTK from source

.github/workflows/build_wheels.yml

@@ -25,7 +25,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-latest,macos-14-large,macos-14,windows-2022]
+        os: [ubuntu-latest,ubuntu-22.04-arm,macos-14-large,macos-14,windows-2022]
         # os: [ubuntu-22.04,ubuntu-22.04-arm,macos-13,macos-13-xlarge,macos-14,macos-14-xlarge,windows-2019,windows-2022]
 
     steps:
@@ -42,7 +42,7 @@ jobs:
       - name: Compile and Build wheels
         uses: pypa/cibuildwheel@v2.20.0
         env:
-            CIBW_ARCHS_LINUX: x86_64
+            CIBW_ARCHS_LINUX: auto
             CIBW_ARCHS_WINDOWS: AMD64
             CIBW_SKIP: "*musllinux*"
             CIBW_BUILD_VERBOSITY: 1

.github/workflows/prebuild.sh

@@ -15,7 +15,15 @@ ls -lh ..
 # Download and build VTK
 LIB_LOCATION=build
 if [[ $1 =~ ubuntu-.* ]]; then
-  VTK_BINARY=vtk-wheel-sdk-9.3.1-cp310-cp310-manylinux_2_17_x86_64.manylinux2014_x86_64.tar.xz
+  # Kitware publishes the VTK wheel-SDK for x86_64 only; there is no linux aarch64
+  # build at any released version, so on aarch64 we build VTK from source instead.
+  # Note this branch previously matched on OS alone, so an arm runner would have
+  # downloaded the x86_64 SDK.
+  if [[ "$(uname -m)" == "aarch64" || "$(uname -m)" == "arm64" ]]; then
+    VTK_FROM_SOURCE=1
+  else
+    VTK_BINARY=vtk-wheel-sdk-9.3.1-cp310-cp310-manylinux_2_17_x86_64.manylinux2014_x86_64.tar.xz
+  fi
   LIB_SUFFIX=so
   MAKEFLAGS="-- -j 8"
 elif [[ $1 =~ macos-.*-large ]]; then
@@ -47,11 +55,56 @@ cmake \
 
 cmake --build eigen/build --target install $MAKEFLAGS $CMAKE_RELEASE_COMMAND
 
-# Install VTK from binary wheels provided by Kitware
 mkdir -p install/vtk install/vtk/shared
-curl -L https://www.vtk.org/files/release/9.3/${VTK_BINARY} -o ./install/vtk/vtk-wheel-sdk.tar.xz
-tar -xJvf ./install/vtk/vtk-wheel-sdk.tar.xz --strip-components 1 -C $PWD/install/vtk
-ln $(find $PWD/install/vtk/${LIB_LOCATION} -name "*.${LIB_SUFFIX}") install/vtk/shared
+if [[ -n "${VTK_FROM_SOURCE:-}" ]]; then
+  # Build only the modules greedy's CMakeLists requires. Refusing the
+  # Rendering/Qt/Views/Web groups is what keeps this cheap: the trimmed build is a
+  # few minutes, where a full VTK build would dominate the job.
+  git clone --depth 1 -b v9.3.1 https://github.com/Kitware/VTK.git VTK
+  cmake \
+      -DCMAKE_BUILD_TYPE=Release \
+      -DBUILD_SHARED_LIBS=OFF \
+      -DBUILD_TESTING=OFF \
+      -DVTK_BUILD_TESTING=OFF \
+      -DVTK_BUILD_EXAMPLES=OFF \
+      -DVTK_BUILD_DOCUMENTATION=OFF \
+      -DCMAKE_POSITION_INDEPENDENT_CODE=ON \
+      -DVTK_GROUP_ENABLE_Rendering=DONT_WANT \
+      -DVTK_GROUP_ENABLE_Qt=DONT_WANT \
+      -DVTK_GROUP_ENABLE_Views=DONT_WANT \
+      -DVTK_GROUP_ENABLE_Web=DONT_WANT \
+      -DVTK_GROUP_ENABLE_Imaging=DONT_WANT \
+      -DVTK_GROUP_ENABLE_MPI=DONT_WANT \
+      -DVTK_GROUP_ENABLE_StandAlone=DONT_WANT \
+      -DVTK_MODULE_ENABLE_VTK_CommonCore=YES \
+      -DVTK_MODULE_ENABLE_VTK_IOCore=YES \
+      -DVTK_MODULE_ENABLE_VTK_IOLegacy=YES \
+      -DVTK_MODULE_ENABLE_VTK_IOPLY=YES \
+      -DVTK_MODULE_ENABLE_VTK_IOGeometry=YES \
+      -DVTK_MODULE_ENABLE_VTK_IOImage=YES \
+      -DVTK_MODULE_ENABLE_VTK_IOXML=YES \
+      -DVTK_MODULE_ENABLE_VTK_FiltersCore=YES \
+      -DVTK_MODULE_ENABLE_VTK_FiltersGeneral=YES \
+      -DVTK_MODULE_ENABLE_VTK_FiltersModeling=YES \
+      -DCMAKE_INSTALL_PREFIX=$PWD/install/vtk \
+      -B VTK/build \
+      VTK
+  cmake --build VTK/build --target install $MAKEFLAGS $CMAKE_RELEASE_COMMAND
+
+  # Expose the config where the wheel-SDK would have put it, so CIBW_ENVIRONMENT's
+  # VTK_DIR needs no per-architecture variant. VTK's exported targets resolve library
+  # paths RELATIVE to the config file (CMake walks three levels up from
+  # vtk-9.3.1.data/headers/cmake), which is why VTK installs into install/vtk above.
+  mkdir -p install/vtk/vtk-9.3.1.data/headers
+  ln -sfn "$(dirname "$(find $PWD/install/vtk -name 'vtk-config.cmake' | head -1)")" \
+          install/vtk/vtk-9.3.1.data/headers/cmake
+  # Static build: nothing for auditwheel to bundle, so install/vtk/shared stays empty.
+else
+  # Install VTK from binary wheels provided by Kitware
+  curl -L https://www.vtk.org/files/release/9.3/${VTK_BINARY} -o ./install/vtk/vtk-wheel-sdk.tar.xz
+  tar -xJvf ./install/vtk/vtk-wheel-sdk.tar.xz --strip-components 1 -C $PWD/install/vtk
+  ln $(find $PWD/install/vtk/${LIB_LOCATION} -name "*.${LIB_SUFFIX}") install/vtk/shared
+fi
 
 # Link the shared libraries needed for delocate into a simple directory