Run both tests pybind11 and nanobind in CI

Assisted-by: Cursor/Composer-2

Signed-off-by: Aleksandr Motsjonov <soswow@gmail.com>

Author: soswow

.github/workflows/build-steps.yml

@@ -88,6 +88,11 @@ on:
         type: string
       build_local_deps:
         type: string
+      # When set (e.g. `both`), CMake builds pybind11 and/or nanobind per OIIO
+      # docs; dependency scripts install the `nanobind` pip package when needed.
+      oiio_python_bindings_backend:
+        type: string
+        default: ''
     secrets:
         PASSED_GITHUB_TOKEN:
           required: false
@@ -136,6 +141,7 @@ jobs:
       OpenImageIO_BUILD_LOCAL_DEPS: ${{inputs.build_local_deps}}
       SETENVS: ${{inputs.setenvs}}
       DEPCMDS: ${{inputs.depcmds}}
+      OIIO_PYTHON_BINDINGS_BACKEND: ${{ inputs.oiio_python_bindings_backend }}
 
     steps:
       - name: install nodejs20glibc2.17

.github/workflows/ci.yml

@@ -355,6 +355,7 @@ jobs:
       required_deps: ${{ matrix.required_deps || 'all' }}
       optional_deps: ${{ matrix.optional_deps || 'CUDAToolkit;DCMTK;JXL;Nuke;OpenGL;openjph;OpenVDB;Ptex;pystring;Qt5;R3DSDK;' }}${{matrix.optional_deps_append}}
       build_local_deps: ${{ matrix.build_local_deps }}
+      oiio_python_bindings_backend: ${{ matrix.oiio_python_bindings_backend || '' }}
     strategy:
       fail-fast: false
       matrix:
@@ -381,6 +382,7 @@ jobs:
 
           - desc: latest releases gcc13 C++20 py3.12 avx2 exr3.4 ocio2.4
             nametag: linux-latest-releases
+            oiio_python_bindings_backend: both
             runner: ubuntu-24.04
             cc_compiler: gcc-13
             cxx_compiler: g++-13
@@ -656,6 +658,7 @@ jobs:
       required_deps: ${{ matrix.required_deps || 'all' }}
       optional_deps: ${{ matrix.optional_deps || 'Nuke;R3DSDK;' }}${{matrix.optional_deps_append}}
       build_local_deps: ${{ matrix.build_local_deps }}
+      oiio_python_bindings_backend: ${{ matrix.oiio_python_bindings_backend || '' }}
     strategy:
       fail-fast: false
       matrix:
@@ -676,6 +679,7 @@ jobs:
           - desc: MacOS-14-ARM aclang15/C++20/py3.13
             runner: macos-14
             nametag: macos14-arm-py313
+            oiio_python_bindings_backend: both
             cc_compiler: /usr/bin/clang
             cxx_compiler: /usr/bin/clang++
             cxx_std: 20
@@ -739,6 +743,7 @@ jobs:
       required_deps: ${{ matrix.required_deps || 'all' }}
       optional_deps: ${{ matrix.optional_deps || 'BZip2;CUDAToolkit;DCMTK;FFmpeg;GIF;JXL;Libheif;LibRaw;Nuke;OpenCV;OpenGL;OpenJPEG;openjph;OpenCV;OpenVDB;Ptex;pystring;Qt5;Qt6;TBB;R3DSDK;${{matrix.optional_deps_append}}' }}
       build_local_deps: ${{ matrix.build_local_deps }}
+      oiio_python_bindings_backend: ${{ matrix.oiio_python_bindings_backend || '' }}
     strategy:
       fail-fast: false
       matrix:
@@ -753,6 +758,7 @@ jobs:
           - desc: Windows-2025 VS2022
             runner: windows-2025
             nametag: windows-2025
+            oiio_python_bindings_backend: both
             generator: "Visual Studio 17 2022"
             python_ver: "3.12"
             ctest_test_timeout: "240"

src/build-scripts/ci-build.bash

@@ -25,6 +25,10 @@ if [[ "$USE_SIMD" != "" ]] ; then
     OIIO_CMAKE_FLAGS="$OIIO_CMAKE_FLAGS -DUSE_SIMD=$USE_SIMD"
 fi
 
+if [[ -n "${OIIO_PYTHON_BINDINGS_BACKEND:-}" ]] ; then
+    OIIO_CMAKE_FLAGS="$OIIO_CMAKE_FLAGS -DOIIO_PYTHON_BINDINGS_BACKEND=${OIIO_PYTHON_BINDINGS_BACKEND}"
+fi
+
 if [[ -n "$CODECOV" ]] ; then
     OIIO_CMAKE_FLAGS="$OIIO_CMAKE_FLAGS -DCODECOV=${CODECOV}"
 fi

src/build-scripts/gh-installdeps.bash

@@ -230,5 +230,14 @@ fi
 df -h .
 df -h /host/root || true
 
+# nanobind's CMake config is discovered via `python -m nanobind --cmake_dir`.
+if [[ "${OIIO_PYTHON_BINDINGS_BACKEND:-}" == "both" || "${OIIO_PYTHON_BINDINGS_BACKEND:-}" == "nanobind" ]] ; then
+    if [[ "$ASWF_ORG" != ""  ]] ; then
+        time pip3 install nanobind || true
+    else
+        time pip3${PIP_SUFFIX} install nanobind
+    fi
+fi
+
 # Save the env for use by other stages
 src/build-scripts/save-env.bash

src/build-scripts/gh-win-installdeps.bash

@@ -39,6 +39,10 @@ elif [[ "$PYTHON_VERSION" == "3.14" ]] ; then
 fi
 pip install numpy
 
+if [[ "${OIIO_PYTHON_BINDINGS_BACKEND:-}" == "both" || "${OIIO_PYTHON_BINDINGS_BACKEND:-}" == "nanobind" ]] ; then
+    "${Python_EXECUTABLE:-python}" -m pip install nanobind
+fi
+
 
 # In case we need vcpkg, example:
 # echo "All pre-installed VCPkg installs:"

src/build-scripts/install_homebrew_deps.bash

@@ -64,6 +64,10 @@ echo ""
 echo "After brew installs:"
 brew list --versions
 
+if [[ "${OIIO_PYTHON_BINDINGS_BACKEND:-}" == "both" || "${OIIO_PYTHON_BINDINGS_BACKEND:-}" == "nanobind" ]] ; then
+    python3 -m pip install nanobind
+fi
+
 # Set up paths. These will only affect the caller if this script is
 # run with 'source' rather than in a separate shell.
 export PATH=${HOMEBREW_PREFIX}/opt/qt5/bin:$PATH