.github/workflows/ci.yml

name: CI

on:
  # Run on Wednesday and Friday at 06:17 UTC.
  schedule:
    - cron: "17 6 * * 3,5"
  workflow_dispatch:
  pull_request:
    types:
      - opened
      - synchronize
      - reopened
      - ready_for_review

permissions: read-all

concurrency:
  group: test-${{ github.ref }}
  cancel-in-progress: true

env:
  PYTHONDEVMODE: 1
  PIP_BREAK_SYSTEM_PACKAGES: 1
  PIP_ONLY_BINARY: numpy
  FORCE_COLOR: 3
  PYTEST_TIMEOUT: 300
  # For cmake:
  VERBOSE: 1
  CMAKE_COLOR_DIAGNOSTICS: 1

jobs:
  # This is the "main" test suite, which tests a large number of different
  # versions of default compilers and Python versions in GitHub Actions.
  # It is in two parts: one that always runs, and one that runs on non-draft
  standard-small:
    if: github.event.action != 'ready_for_review'
    strategy:
      fail-fast: false
      matrix:
        include:
          - runs-on: ubuntu-22.04
            python-version: '3.9'
            cmake-args: -DPYBIND11_FINDPYTHON=OFF -DPYBIND11_NUMPY_1_ONLY=ON
          - runs-on: ubuntu-latest
            python-version: '3.13'
            cmake-args: -DCMAKE_CXX_STANDARD=23 -DPYBIND11_SIMPLE_GIL_MANAGEMENT=ON
          - runs-on: ubuntu-latest
            python-version: '3.14t'
            cmake-args: -DCMAKE_CXX_STANDARD=17 -DPYBIND11_TEST_SMART_HOLDER=ON
          - runs-on: ubuntu-latest
            python-version: 'pypy-3.11-v7.3.23'
            cmake-args: -DCMAKE_CXX_STANDARD=17
          - runs-on: ubuntu-latest
            python-version: 'graalpy-25.0'
            cmake-args: -DCMAKE_CXX_STANDARD=20
          - runs-on: ubuntu-latest
            python-version: 'graalpy-25.3'
            cmake-args: -DCMAKE_CXX_STANDARD=20
          - runs-on: ubuntu-latest
            python-version: '3.15'
            cmake-args: -DCMAKE_CXX_STANDARD=20
          - runs-on: macos-latest
            python-version: '3.14'
            cmake-args: -DCMAKE_CXX_STANDARD=14
          - runs-on: windows-2022
            python-version: '3.9'
            cmake-args: -DPYBIND11_FINDPYTHON=OFF


    name: 🐍
    uses: ./.github/workflows/reusable-standard.yml
    with:
      runs-on: ${{ matrix.runs-on }}
      python-version: ${{ matrix.python-version }}
      cmake-args: ${{ matrix.cmake-args }}

  # Build the test suite against the precompiled pybind11 static library; a
  # definition missing from the -inl.h split shows up here as a link error.
  precompile:
    if: github.event.pull_request.draft == false
    strategy:
      fail-fast: false
      matrix:
        include:
          - runs-on: ubuntu-latest
            python-version: '3.13'
          # free-threaded: compiles the Py_GIL_DISABLED-only code in the -inl.h files
          - runs-on: ubuntu-latest
            python-version: '3.14t'
          - runs-on: macos-latest
            python-version: '3.13'
          - runs-on: windows-2022
            python-version: '3.13'

    name: ⚡
    uses: ./.github/workflows/reusable-standard.yml
    with:
      runs-on: ${{ matrix.runs-on }}
      python-version: ${{ matrix.python-version }}
      cmake-args: -DPYBIND11_TEST_PRECOMPILE=ON

  standard-large:
    if: github.event.pull_request.draft == false
    strategy:
      fail-fast: false
      matrix:
        include:
          - runs-on: ubuntu-latest
            python-version: '3.9'
            cmake-args: -DPYBIND11_FINDPYTHON=ON -DCMAKE_CXX_STANDARD=17
          - runs-on: ubuntu-latest
            python-version: '3.10'
            cmake-args: -DCMAKE_CXX_STANDARD=20
          - runs-on: ubuntu-latest
            python-version: '3.12'
            cmake-args: -DPYBIND11_TEST_SMART_HOLDER=ON -DPYBIND11_SIMPLE_GIL_MANAGEMENT=ON
          - runs-on: ubuntu-latest
            python-version: '3.14'
            cmake-args: -DCMAKE_CXX_STANDARD=14
          - runs-on: ubuntu-latest
            python-version: '3.15t'
            cmake-args: -DCMAKE_CXX_STANDARD=17 -DPYBIND11_TEST_SMART_HOLDER=ON

          # No SciPy for macOS ARM
          - runs-on: macos-15-intel
            python-version: '3.9'
            cmake-args: -DCMAKE_CXX_STANDARD=14
          - runs-on: macos-15-intel
            python-version: '3.13'
            cmake-args: -DCMAKE_CXX_STANDARD=11
          - runs-on: macos-latest
            python-version: '3.12'
            cmake-args: -DCMAKE_CXX_STANDARD=17 -DPYBIND11_DISABLE_HANDLE_TYPE_NAME_DEFAULT_IMPLEMENTATION=ON
          - runs-on: macos-latest
            python-version: '3.14t'
            cmake-args: -DCMAKE_CXX_STANDARD=20
          - runs-on: macos-latest
            python-version: '3.15'
            cmake-args: -DCMAKE_CXX_STANDARD=17
          - runs-on: macos-latest
            python-version: 'pypy-3.11-v7.3.23'
          - runs-on: macos-latest
            python-version: 'graalpy-25.0'
          - runs-on: macos-latest
            python-version: 'graalpy-25.3'

          - runs-on: windows-latest
            python-version: '3.9'
            cmake-args: -DPYBIND11_TEST_SMART_HOLDER=ON
          - runs-on: windows-2022
            python-version: '3.9'
            cmake-args: -DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreaded -DPYBIND11_NUMPY_1_ONLY=ON
          # This needs a python built with MTd
          # - runs-on: windows-2022
          #   python-version: '3.11'
          #   cmake-args: -DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreadedDebug
          - runs-on: windows-2022
            python-version: '3.10'
            cmake-args: -DPYBIND11_TEST_SMART_HOLDER=ON -DCMAKE_CXX_FLAGS="/GR /EHsc"
          - runs-on: windows-2022
            python-version: '3.13'
            cmake-args: -DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreadedDebugDLL
          - runs-on: windows-latest
            python-version: '3.14'
            cmake-args: -DCMAKE_CXX_STANDARD=20
          - runs-on: windows-latest
            python-version: '3.14t'
            cmake-args: -DCMAKE_CXX_STANDARD=23
          - runs-on: windows-latest
            python-version: '3.15'
            cmake-args: -DCMAKE_CXX_STANDARD=20
          - runs-on: windows-latest
            python-version: 'pypy3.11'
            cmake-args: -DCMAKE_CXX_STANDARD=20
          # The setup-python action currently doesn't have graalpy for windows
          # See https://github.com/actions/setup-python/pull/880

    name: 🐍
    uses: ./.github/workflows/reusable-standard.yml
    with:
      runs-on: ${{ matrix.runs-on }}
      python-version: ${{ matrix.python-version }}
      cmake-args: ${{ matrix.cmake-args }}

  # This checks inplace builds with C++11
  inplace:
    if: github.event.pull_request.draft == false
    strategy:
      fail-fast: false
      matrix:
        include:
          - runs-on: ubuntu-latest
            python-version: '3.9'
          - runs-on: macos-latest
            python-version: '3.12'
          - runs-on: windows-latest
            python-version: '3.11'

    name: "🐍 ${{ matrix.python-version }} • ${{ matrix.runs-on }} • x64 inplace C++14"
    runs-on: ${{ matrix.runs-on }}
    timeout-minutes: 90

    steps:
    - uses: actions/checkout@v7

    - name: Setup Python ${{ matrix.python-version }}
      uses: actions/setup-python@v7
      with:
        python-version: ${{ matrix.python-version }}
        allow-prereleases: true

    - name: Install uv
      uses: astral-sh/setup-uv@v10.2.0
      with:
        enable-cache: true

    - name: Prepare env
      run: uv pip install --python=python --system -r tests/requirements.txt

    # TODO Resolve Windows Ninja shared object issue on Python 3.9+
    - name: Use Ninja except on Windows
      if: runner.os != 'Windows'
      run: echo "CMAKE_GENERATOR=Ninja" >> "$GITHUB_ENV"

    # More-or-less randomly adding a few extra flags here.
    # In particular, use this one to test the next ABI bump (internals version).
    - name: Configure
      run: >
        cmake -S. -B.
        -DPYBIND11_WERROR=ON
        -DPYBIND11_SIMPLE_GIL_MANAGEMENT=ON
        -DPYBIND11_PYTEST_ARGS=-v
        -DDOWNLOAD_CATCH=ON
        -DDOWNLOAD_EIGEN=ON
        -DCMAKE_CXX_STANDARD=14
        -DPYBIND11_INTERNALS_VERSION=10000000

    # Checks to makes sure defining `_` is allowed
    # Triggers EHsc missing error on Windows
    - name: Add underscore check
      if: runner.os != 'Windows'
      run: cmake -S. -B. -DCMAKE_CXX_FLAGS="-D_=1"

    - name: Build
      run: cmake --build .

    - name: Python tests
      run: cmake --build . --target pytest

    - name: Compiled tests
      timeout-minutes: 3
      run: cmake --build . --target cpptest

    - name: Interface test
      run: cmake --build . --target test_cmake_build

    - name: Visibility test
      run: cmake --build . --target test_cross_module_rtti


  manylinux:
    name: Manylinux on 🐍 ${{ matrix.python-version }} (${{ matrix.container }})
    if: github.event.pull_request.draft == false
    strategy:
      fail-fast: false
      matrix:
        include:
          - container: quay.io/pypa/manylinux_2_28_x86_64:latest
            python-version: '3.14t'
          - container: quay.io/pypa/musllinux_1_2_x86_64:latest
            python-version: '3.14t'
    runs-on: ubuntu-latest
    timeout-minutes: 40
    container: ${{ matrix.container }}
    steps:
      - uses: actions/checkout@v7
        with:
          fetch-depth: 0

      - name: Prepare uv's path
        run: echo "$HOME/.local/bin" >> $GITHUB_PATH

      - name: Install ninja
        run: uv tool install ninja

      - name: Configure via preset
        run: cmake --preset venv -DPYBIND11_CREATE_WITH_UV="${{ matrix.python-version }}"

      - name: Build C++11
        run: cmake --build --preset venv

      - name: Python tests C++11
        run: cmake --build --preset testsvenv -t pytest

  # Testing on clang using the excellent silkeh clang docker images
  clang:
    if: github.event.pull_request.draft == false
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        include:
          - clang: 5
            std: 14
            container: "silkeh/clang:5@sha256:68f994994d0c12563f4ce6bf34d78a19dc503e8e48778e4af33cf49abcd27133"
            use_bullseye_snapshot: true
          - clang: 11
            std: 20
            container: "silkeh/clang:11-bullseye@sha256:5d4e67f5a2de1b26f632b88343dc63b894c8ddc9b068114894cc56de8e888b61"
            use_bullseye_snapshot: true
          - clang: 16
            std: 20
            container: "silkeh/clang:16-bookworm"
          - clang: 18
            std: 20
            cxx_flags: "-Werror -Wall -Wextra -Wwrite-strings -Wunreachable-code -Wpointer-arith -Wredundant-decls -Wunused-template"
            container: "silkeh/clang:18-bookworm"

    name: "🐍 3 • Clang ${{ matrix.clang }} • C++${{ matrix.std }} • x64${{ matrix.cxx_flags && ' • cxx_flags' || '' }}"
    container: "${{ matrix.container }}"
    timeout-minutes: 90

    steps:
    - uses: actions/checkout@v7

    - name: Use the pinned Debian snapshot for legacy Clang — see PR 6175
      if: matrix.use_bullseye_snapshot
      run: |
        # Clang 5 and 11 have no Bookworm images. Keep their Bullseye package
        # set coherent after the end of Bullseye LTS by using its final snapshot.
        rm -f /etc/apt/sources.list.d/*
        printf '%s\n' \
          'deb [check-valid-until=no] https://snapshot.debian.org/archive/debian/20260831T000000Z/ bullseye main' \
          'deb [check-valid-until=no] https://snapshot.debian.org/archive/debian/20260831T000000Z/ bullseye-updates main' \
          'deb [check-valid-until=no] https://snapshot.debian.org/archive/debian-security/20260831T000000Z/ bullseye-security main' \
          > /etc/apt/sources.list

    - name: Install Python 3 and test dependencies
      run: apt-get update && apt-get install -y python3-dev python3-numpy python3-pytest libeigen3-dev

    - name: Configure
      shell: bash
      run: >
        cmake -S . -B build
        -DPYBIND11_WERROR=ON
        -DDOWNLOAD_CATCH=ON
        -DCMAKE_CXX_STANDARD=${{ matrix.std }}
        -DCMAKE_CXX_FLAGS="${{ matrix.cxx_flags }}"
        -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")

    - name: Build
      run: cmake --build build -j 2

    - name: Python tests
      run: cmake --build build --target pytest

    - name: C++ tests
      timeout-minutes: 3
      run: cmake --build build --target cpptest

    - name: Interface test
      run: cmake --build build --target test_cmake_build

    - name: Visibility test
      run: cmake --build build --target test_cross_module_rtti

  # Testing NVCC; forces sources to behave like .cu files
  cuda:
    runs-on: ubuntu-latest
    name: "🐍 3.10 • CUDA 12.2 • Ubuntu 22.04"
    container: nvidia/cuda:12.2.0-devel-ubuntu22.04
    timeout-minutes: 90

    steps:
    - uses: actions/checkout@v7

    # tzdata will try to ask for the timezone, so set the DEBIAN_FRONTEND
    - name: Install 🐍 3
      run: apt-get update && DEBIAN_FRONTEND="noninteractive" apt-get install -y cmake git python3-dev python3-pytest python3-numpy

    - name: Configure
      run: cmake -S . -B build -DPYBIND11_CUDA_TESTS=ON -DPYBIND11_WERROR=ON -DDOWNLOAD_CATCH=ON

    - name: Build
      run: cmake --build build -j2 --verbose

    - name: Python tests
      run: cmake --build build --target pytest


# TODO: Internal compiler error - report to NVidia
#  # Testing CentOS 8 + PGI compilers
#  centos-nvhpc8:
#    runs-on: ubuntu-latest
#    name: "🐍 3 • CentOS8 / PGI 20.11 • x64"
#    container: centos:8
#
#    steps:
#    - uses: actions/checkout@v7
#
#    - name: Add Python 3 and a few requirements
#      run: yum update -y && yum install -y git python3-devel python3-numpy python3-pytest make environment-modules
#
#    - name: Install CMake with pip
#      run: |
#        python3 -m pip install --upgrade pip
#        python3 -m pip install cmake --prefer-binary
#
#    - name: Install NVidia HPC SDK
#      run: >
#        yum -y install
#        https://developer.download.nvidia.com/hpc-sdk/20.11/nvhpc-20-11-20.11-1.x86_64.rpm
#        https://developer.download.nvidia.com/hpc-sdk/20.11/nvhpc-2020-20.11-1.x86_64.rpm
#
#    - name: Configure
#      shell: bash
#      run: |
#        source /etc/profile.d/modules.sh
#        module load /opt/nvidia/hpc_sdk/modulefiles/nvhpc/20.11
#        cmake -S . -B build -DDOWNLOAD_CATCH=ON -DCMAKE_CXX_STANDARD=14 -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")
#
#    - name: Build
#      run: cmake --build build -j 2 --verbose
#
#    - name: Python tests
#      run: cmake --build build --target pytest
#
#    - name: C++ tests
#      run: cmake --build build --target cpptest
#
#    - name: Interface test
#      run: cmake --build build --target test_cmake_build


  # Testing on Ubuntu + NVHPC (previous PGI) compilers, which seems to require more workarounds
  ubuntu-nvhpc:
    if: github.event.pull_request.draft == false
    runs-on: ubuntu-24.04
    name: "🐍 3 • NVHPC 26.5 • C++17 • x64"
    timeout-minutes: 90

    env:
      # tzdata will try to ask for the timezone, so set the DEBIAN_FRONTEND
      DEBIAN_FRONTEND: 'noninteractive'
    steps:
    - uses: actions/checkout@v7

    - name: Clean out unused stuff to save space
      run: |
        sudo rm -rf /usr/local/lib/android /usr/share/dotnet /opt/ghc /opt/hostedtoolcache/CodeQL
        sudo apt-get clean

    - name: Install 🐍 3
      run: |
        sudo apt-get update -y
        sudo apt-get install -y cmake environment-modules git python3-dev python3-pip python3-numpy
        python3 -m pip install --upgrade pip
        python3 -m pip install --upgrade pytest

    # Downloaded with curl instead of apt: the Akamai CDN in front of
    # developer.download.nvidia.com intermittently 404s, and apt neither
    # retries 404s nor resumes a broken 5 GB transfer.
    - name: Install NVHPC
      run: |
        curl -fSLO --retry 10 --retry-all-errors --retry-delay 15 --continue-at - \
          https://developer.download.nvidia.com/hpc-sdk/ubuntu/amd64/nvhpc-26-5_26.5-0_amd64.deb
        sudo apt-get install -y --no-install-recommends ./nvhpc-26-5_26.5-0_amd64.deb
        rm nvhpc-26-5_26.5-0_amd64.deb

    # On some systems, you many need further workarounds:
    # https://github.com/pybind/pybind11/pull/2475
    - name: Configure
      shell: bash
      run: |
        source /etc/profile.d/modules.sh
        module load /opt/nvidia/hpc_sdk/modulefiles/nvhpc/26.5
        cmake -S . -B build -DDOWNLOAD_CATCH=ON \
                            -DCMAKE_CXX_STANDARD=17 \
                            -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)") \
                            -DCMAKE_CXX_FLAGS="-Wc,--pending_instantiations=0" \
                            -DPYBIND11_TEST_FILTER="test_smart_ptr.cpp"

    - name: Build
      run: cmake --build build -j $(nproc) --verbose

    - name: Python tests
      run: cmake --build build --target pytest

    - name: C++ tests
      timeout-minutes: 3
      run: cmake --build build --target cpptest

    - name: Interface test
      run: cmake --build build --target test_cmake_build

    - name: Visibility test
      run: cmake --build build --target test_cross_module_rtti

  # Testing on GCC using the GCC docker images (only recent images supported)
  gcc:
    if: github.event.pull_request.draft == false
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        include:
          - gcc: 9
            std: 20
            container: "gcc:9-bullseye@sha256:a9aba821155db99d0800920f27bf3a94ead6f9dedf330a2e2ce38da73f5370e3"
            use_bullseye_snapshot: true
          - gcc: 10
            std: 17
            container: "gcc:10-bullseye@sha256:19b31d0b2b263047b173e4e253d91f199d99c082973f13604d2913252c13309e"
            use_bullseye_snapshot: true
          - gcc: 13
            std: 20
            container: "gcc:13"
            cxx_flags: "-Wall -Wextra -Wwrite-strings -Wunreachable-code -Wpointer-arith -Wredundant-decls"

    name: "🐍 3 • GCC ${{ matrix.gcc }} • C++${{ matrix.std }} • x64${{ matrix.cxx_flags && ' • cxx_flags' || '' }}"
    container: "${{ matrix.container }}"
    timeout-minutes: 90

    steps:
    - uses: actions/checkout@v7

    - name: Use the pinned Debian snapshot for legacy GCC — see PR 6175
      if: matrix.use_bullseye_snapshot
      run: |
        # The GCC 9 and 10 Bookworm images cannot run Bookworm's apt with
        # their older libstdc++. Keep the coherent Bullseye userspace instead.
        rm -f /etc/apt/sources.list.d/*
        printf '%s\n' \
          'deb [check-valid-until=no] https://snapshot.debian.org/archive/debian/20260831T000000Z/ bullseye main' \
          'deb [check-valid-until=no] https://snapshot.debian.org/archive/debian/20260831T000000Z/ bullseye-updates main' \
          'deb [check-valid-until=no] https://snapshot.debian.org/archive/debian-security/20260831T000000Z/ bullseye-security main' \
          > /etc/apt/sources.list

    - name: Add Python 3
      run: apt-get update; apt-get install -y python3-dev python3-numpy python3-pytest python3-pip libeigen3-dev

    - name: Update pip
      run: python3 -m pip install --upgrade pip

    - name: Update CMake
      uses: jwlawson/actions-setup-cmake@v2.2

    - name: Configure
      shell: bash
      run: >
        cmake -S . -B build
        -DPYBIND11_WERROR=ON
        -DDOWNLOAD_CATCH=ON
        -DCMAKE_CXX_STANDARD=${{ matrix.std }}
        -DCMAKE_CXX_FLAGS="${{ matrix.cxx_flags }}"
        -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")

    - name: Build
      run: cmake --build build -j 2

    - name: Python tests
      run: cmake --build build --target pytest

    - name: C++ tests
      timeout-minutes: 3
      run: cmake --build build --target cpptest

    - name: Interface test
      run: cmake --build build --target test_cmake_build

    - name: Visibility test
      run: cmake --build build --target test_cross_module_rtti

  # Testing on ICC using the oneAPI apt repo
  icc:
    if: github.event.pull_request.draft == false
    runs-on: ubuntu-22.04
    timeout-minutes: 90

    name: "🐍 3 • ICC latest • x64"

    steps:
    - uses: actions/checkout@v7

    - name: Add apt repo
      run: |
        sudo apt-get update
        sudo apt-get install -y wget build-essential pkg-config cmake ca-certificates gnupg
        wget https://apt.repos.intel.com/intel-gpg-keys/GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
        sudo apt-key add GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
        echo "deb https://apt.repos.intel.com/oneapi all main" | sudo tee /etc/apt/sources.list.d/oneAPI.list

    - name: Add ICC & Python 3
      run: sudo apt-get update; sudo apt-get install -y intel-oneapi-compiler-dpcpp-cpp-and-cpp-classic cmake python3-dev python3-numpy python3-pytest python3-pip

    - name: Update pip
      run: |
        set +e; source /opt/intel/oneapi/setvars.sh; set -e
        python3 -m pip install --upgrade pip

    - name: Install dependencies
      run: |
        set +e; source /opt/intel/oneapi/setvars.sh; set -e
        python3 -m pip install -r tests/requirements.txt

    - name: Configure C++11
      run: |
        set +e; source /opt/intel/oneapi/setvars.sh; set -e
        cmake -S . -B build-11     \
        -DPYBIND11_WERROR=ON    \
        -DDOWNLOAD_CATCH=ON     \
        -DDOWNLOAD_EIGEN=OFF    \
        -DCMAKE_CXX_STANDARD=11             \
        -DCMAKE_CXX_COMPILER=$(which icpc)  \
        -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")

    - name: Build C++11
      run: |
        set +e; source /opt/intel/oneapi/setvars.sh; set -e
        cmake --build build-11 -j 2 -v

    - name: Python tests C++11
      run: |
        set +e; source /opt/intel/oneapi/setvars.sh; set -e
        sudo service apport stop
        cmake --build build-11 --target check

    - name: C++ tests C++11
      timeout-minutes: 3
      run: |
        set +e; source /opt/intel/oneapi/setvars.sh; set -e
        cmake --build build-11 --target cpptest

    - name: Interface test C++11
      run: |
        set +e; source /opt/intel/oneapi/setvars.sh; set -e
        cmake --build build-11 --target test_cmake_build

    - name: Visibility test
      run: |
        set +e; source /opt/intel/oneapi/setvars.sh; set -e
        cmake --build build-11 --target test_cross_module_rtti

    - name: Configure C++17
      run: |
        set +e; source /opt/intel/oneapi/setvars.sh; set -e
        cmake -S . -B build-17     \
        -DPYBIND11_WERROR=ON    \
        -DDOWNLOAD_CATCH=ON     \
        -DDOWNLOAD_EIGEN=OFF    \
        -DCMAKE_CXX_STANDARD=17             \
        -DCMAKE_CXX_COMPILER=$(which icpc)  \
        -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")

    - name: Build C++17
      run: |
        set +e; source /opt/intel/oneapi/setvars.sh; set -e
        cmake --build build-17 -j 2 -v

    - name: Python tests C++17
      run: |
        set +e; source /opt/intel/oneapi/setvars.sh; set -e
        sudo service apport stop
        cmake --build build-17 --target check

    - name: C++ tests C++17
      timeout-minutes: 3
      run: |
        set +e; source /opt/intel/oneapi/setvars.sh; set -e
        cmake --build build-17 --target cpptest

    - name: Interface test C++17
      run: |
        set +e; source /opt/intel/oneapi/setvars.sh; set -e
        cmake --build build-17 --target test_cmake_build

    - name: Visibility test
      run: |
        set +e; source /opt/intel/oneapi/setvars.sh; set -e
        cmake --build build-17 --target test_cross_module_rtti

  # Testing on CentOS (manylinux uses a centos base).
  centos:
    if: github.event.pull_request.draft == false
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        container:
          - "almalinux:8"
          - "almalinux:9"

    name: "🐍 3 • ${{ matrix.container }} • x64"
    container: "${{ matrix.container }}"
    timeout-minutes: 90

    steps:
    - name: Latest actions/checkout
      uses: actions/checkout@v7

    - name: Add Python 3.9
      if: matrix.container == 'almalinux:8'
      run: dnf update -y && dnf install -y python39-devel gcc-c++ make git

    - name: Add Python 3 (default)
      if: matrix.container != 'almalinux:8'
      run: dnf update -y && dnf install -y python3-devel gcc-c++ make git

    - name: Update pip
      run: python3 -m pip install --upgrade pip

    - name: Install dependencies
      run: |
        python3 -m pip install cmake -r tests/requirements.txt

    - name: Ensure NumPy 2 is used (required Python >= 3.9)
      if: matrix.container == 'almalinux:9'
      run: |
        python3 -m pip install 'numpy>=2.0.0b1' 'scipy>=1.13.0rc1'

    - name: Configure
      shell: bash
      run: >
        cmake -S . -B build
        -DCMAKE_BUILD_TYPE=MinSizeRel
        -DPYBIND11_WERROR=ON
        -DDOWNLOAD_CATCH=ON
        -DDOWNLOAD_EIGEN=ON
        -DCMAKE_CXX_STANDARD=11
        -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")

    - name: Build
      run: cmake --build build -j 2

    - name: Python tests
      run: cmake --build build --target pytest

    - name: C++ tests
      timeout-minutes: 3
      run: cmake --build build --target cpptest

    - name: Interface test
      run: cmake --build build --target test_cmake_build

    - name: Visibility test
      run: cmake --build build --target test_cross_module_rtti


  # This tests an "install" with the CMake tools
  install-classic:
    if: github.event.pull_request.draft == false
    name: "🐍 3.11 • Debian • x86 •  Install"
    runs-on: ubuntu-latest
    container: i386/debian:bookworm
    timeout-minutes: 90

    steps:
    # v1 required for i386/debian container; pinned to SHA to prevent dependabot updates
    - uses: actions/checkout@544eadc6bf3d226fd7a7a9f0dc5b5bf7ca0675b9  # v1

    - name: Install requirements
      run: |
        apt-get update
        apt-get install -y git make cmake g++ libeigen3-dev python3-dev python3-pytest

    - name: Configure for install
      run: >
        cmake .
        -DPYBIND11_INSTALL=1 -DPYBIND11_TEST=0
        -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")

    - name: Make and install
      run: make install

    - name: Copy tests to new directory
      run: cp -a tests /pybind11-tests

    - name: Make a new test directory
      run: mkdir /build-tests

    - name: Configure tests
      run: >
        cmake ../pybind11-tests
        -DDOWNLOAD_CATCH=ON
        -DPYBIND11_WERROR=ON
        -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")
      working-directory: /build-tests

    - name: Python tests
      run: make pytest -j 2
      working-directory: /build-tests


  # This verifies that the documentation is not horribly broken, and does a
  # basic validation check on the SDist.
  doxygen:
    if: github.event.pull_request.draft == false
    name: "Documentation build test"
    runs-on: ubuntu-latest
    timeout-minutes: 90

    steps:
    - uses: actions/checkout@v7

    - uses: actions/setup-python@v7
      with:
        python-version: "3.x"

    - name: Install Doxygen
      run: sudo apt-get install -y doxygen librsvg2-bin # Changed to rsvg-convert in 20.04

    - name: Build docs
      run: pipx run nox -s docs

    - name: Make SDist
      run: pipx run nox -s build -- --sdist

    - run: git status --ignored

    - name: Check local include dir
      run: >
        ls pybind11;
        python3 -c "import pybind11, pathlib; assert (a := pybind11.get_include()) == (b := str(pathlib.Path('include').resolve())), f'{a} != {b}'"

    - name: Compare Dists (headers only)
      working-directory: include
      run: |
        python3 -m pip install --user -U ../dist/*.tar.gz
        installed=$(python3 -c "import pybind11; print(pybind11.get_include() + '/pybind11')")
        diff -rq $installed ./pybind11

  win32:
    if: github.event.pull_request.draft == false
    strategy:
      fail-fast: false
      matrix:
        include:
          - python: '3.9'
            args: -DCMAKE_CXX_STANDARD=17
          - python: '3.13'


    name: "🐍 ${{ matrix.python }} • MSVC 2022 • x86 ${{ matrix.args }}"
    runs-on: windows-2022
    timeout-minutes: 90

    steps:
    - uses: actions/checkout@v7

    - name: Setup Python ${{ matrix.python }}
      uses: actions/setup-python@v7
      with:
        python-version: ${{ matrix.python }}
        architecture: x86
        # Python 3.13.4 broken on Windows
        check-latest: >-
          ${{ matrix.python == '3.13' && runner.os == 'Windows' }}

    - name: Update CMake
      uses: jwlawson/actions-setup-cmake@v2.2

    - name: Prepare MSVC
      uses: ilammy/msvc-dev-cmd@v1.13.0
      with:
        arch: x86

    - name: Prepare env
      run: |
        python -m pip install -r tests/requirements.txt

    - name: Configure ${{ matrix.args }}
      run: >
        cmake -S . -B build
        -G "Visual Studio 17 2022" -A Win32
        -DPYBIND11_WERROR=ON
        -DDOWNLOAD_CATCH=ON
        -DDOWNLOAD_EIGEN=ON
        ${{ matrix.args }}
    - name: Build C++11
      run: cmake --build build -j 2

    - name: Python tests
      run: cmake --build build -t pytest

  win32-debug:
    if: github.event.pull_request.draft == false
    strategy:
      fail-fast: false
      matrix:
        include:
          - python: 3.9
            args: -DCMAKE_CXX_STANDARD=20

    name: "🐍 ${{ matrix.python }} • MSVC 2022 (Debug) • x86 ${{ matrix.args }}"
    runs-on: windows-2022
    timeout-minutes: 90

    steps:
    - uses: actions/checkout@v7

    - name: Setup Python ${{ matrix.python }}
      uses: actions/setup-python@v7
      with:
        python-version: ${{ matrix.python }}
        architecture: x86

    - name: Update CMake
      uses: jwlawson/actions-setup-cmake@v2.2

    - name: Prepare MSVC
      uses: ilammy/msvc-dev-cmd@v1.13.0
      with:
        arch: x86

    - name: Prepare env
      run: |
        python -m pip install -r tests/requirements.txt

    - name: Configure ${{ matrix.args }}
      run: >
        cmake -S . -B build
        -G "Visual Studio 17 2022" -A Win32
        -DCMAKE_BUILD_TYPE=Debug
        -DPYBIND11_WERROR=ON
        -DDOWNLOAD_CATCH=ON
        -DDOWNLOAD_EIGEN=ON
        ${{ matrix.args }}
    - name: Build C++11
      run: cmake --build build --config Debug -j 2

    - name: Python tests
      run: cmake --build build --config Debug -t pytest


  windows-2022:
    if: github.event.pull_request.draft == false
    strategy:
      fail-fast: false
      matrix:
        python:
        - 3.9

    name: "🐍 ${{ matrix.python }} • MSVC 2022 C++20 • x64"
    runs-on: windows-2022
    timeout-minutes: 90

    steps:
    - uses: actions/checkout@v7

    - name: Setup Python ${{ matrix.python }}
      uses: actions/setup-python@v7
      with:
        python-version: ${{ matrix.python }}

    - name: Prepare env
      run: python3 -m pip install -r tests/requirements.txt

    - name: Update CMake
      uses: jwlawson/actions-setup-cmake@v2.2

    - name: Configure C++20
      run: >
        cmake -S . -B build
        -DPYBIND11_WERROR=ON
        -DDOWNLOAD_CATCH=ON
        -DDOWNLOAD_EIGEN=ON
        -DCMAKE_CXX_STANDARD=20

    - name: Build C++20
      run: cmake --build build -j 2

    - name: Python tests
      run: cmake --build build --target pytest

    - name: C++20 tests
      timeout-minutes: 3
      run: cmake --build build --target cpptest -j 2

    - name: Interface test C++20
      run: cmake --build build --target test_cmake_build

    - name: Visibility test
      run: cmake --build build --target test_cross_module_rtti

    - name: Configure C++20 - Exercise cmake -DPYBIND11_TEST_OVERRIDE
      run: >
        cmake -S . -B build_partial
        -DPYBIND11_WERROR=ON
        -DDOWNLOAD_CATCH=ON
        -DDOWNLOAD_EIGEN=ON
        -DCMAKE_CXX_STANDARD=20
        "-DPYBIND11_TEST_OVERRIDE=test_call_policies.cpp;test_gil_scoped.cpp;test_thread.cpp"

    - name: Build C++20 - Exercise cmake -DPYBIND11_TEST_OVERRIDE
      run: cmake --build build_partial -j 2

    - name: Python tests - Exercise cmake -DPYBIND11_TEST_OVERRIDE
      run: cmake --build build_partial --target pytest

  mingw:
    if: github.event.pull_request.draft == false
    name: "🐍 3 • windows-latest • ${{ matrix.sys }}"
    runs-on: windows-latest
    timeout-minutes: 90
    defaults:
      run:
        shell: msys2 {0}
    strategy:
      fail-fast: false
      matrix:
        include:
          - sys: mingw32
            env: i686
            extra_install: ""
          - sys: mingw64
            env: x86_64
            extra_install: |
              mingw-w64-x86_64-boost
              mingw-w64-x86_64-python-numpy
              mingw-w64-x86_64-python-scipy
              mingw-w64-x86_64-eigen3
    steps:
    - uses: msys2/setup-msys2@v2
      with:
        msystem: ${{matrix.sys}}
        install: >-
          git
          mingw-w64-${{matrix.env}}-gcc
          mingw-w64-${{matrix.env}}-python-pip
          mingw-w64-${{matrix.env}}-cmake
          mingw-w64-${{matrix.env}}-make
          mingw-w64-${{matrix.env}}-python-pytest
          mingw-w64-${{matrix.env}}-catch
          ${{ matrix.extra_install }}

    - uses: actions/checkout@v7

    - name: Configure C++11
      # LTO leads to many undefined reference like
      # `pybind11::detail::function_call::function_call(pybind11::detail::function_call&&)
      run: >-
        cmake -G "MinGW Makefiles" -DCMAKE_CXX_STANDARD=11 -DPYBIND11_WERROR=ON -DDOWNLOAD_CATCH=ON
        -DPYTHON_EXECUTABLE=$(python -c "import sys; print(sys.executable)")
        -S . -B build

    - name: Build C++11
      run: cmake --build build -j 2

    - name: Python tests C++11
      run: cmake --build build --target pytest -j 2

    - name: C++11 tests
      timeout-minutes: 3
      run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build --target cpptest -j 2

    - name: Interface test C++11
      run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build --target test_cmake_build

    - name: Visibility test
      run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build --target test_cross_module_rtti

    - name: Clean directory
      run: git clean -fdx

    - name: Configure C++14
      run: >-
        cmake -G "MinGW Makefiles" -DCMAKE_CXX_STANDARD=14 -DPYBIND11_WERROR=ON -DDOWNLOAD_CATCH=ON
        -DPYTHON_EXECUTABLE=$(python -c "import sys; print(sys.executable)")
        -S . -B build2

    - name: Build C++14
      run: cmake --build build2 -j 2

    - name: Python tests C++14
      run: cmake --build build2 --target pytest -j 2

    - name: C++14 tests
      timeout-minutes: 3
      run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build2 --target cpptest -j 2

    - name: Interface test C++14
      run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build2 --target test_cmake_build

    - name: Visibility test
      run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build2 --target test_cross_module_rtti

    - name: Clean directory
      run: git clean -fdx

    - name: Configure C++17
      run: >-
        cmake -G "MinGW Makefiles" -DCMAKE_CXX_STANDARD=17 -DPYBIND11_WERROR=ON -DDOWNLOAD_CATCH=ON
        -DPYTHON_EXECUTABLE=$(python -c "import sys; print(sys.executable)")
        -S . -B build3

    - name: Build C++17
      run: cmake --build build3 -j 2

    - name: Python tests C++17
      run: cmake --build build3 --target pytest -j 2

    - name: C++17 tests
      timeout-minutes: 3
      run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build3 --target cpptest -j 2

    - name: Interface test C++17
      run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build3 --target test_cmake_build

    - name: Visibility test
      run: PYTHONHOME=/${{matrix.sys}} PYTHONPATH=/${{matrix.sys}} cmake --build build3 --target test_cross_module_rtti

  windows_clang:
    if: github.event.pull_request.draft == false

    strategy:
      matrix:
        os: [windows-latest]
        python: ['3.10']

    runs-on: "${{ matrix.os }}"
    timeout-minutes: 90

    name: "🐍 ${{ matrix.python }} • ${{ matrix.os }} • clang-latest"

    steps:
      - name: Show env
        run: env

      - name: Checkout
        uses: actions/checkout@v7

      - name: Set up Clang
        uses: egor-tensin/setup-clang@v2

      - name: Setup Python ${{ matrix.python }}
        uses: actions/setup-python@v7
        with:
          python-version: ${{ matrix.python }}

      - name: Update CMake
        uses: jwlawson/actions-setup-cmake@v2.2

      - name: Run pip installs
        run: |
          python -m pip install --upgrade pip
          python -m pip install -r tests/requirements.txt

      - name: Show Clang++ version
        run: clang++ --version

      - name: Show CMake version
        run: cmake --version

      # TODO: WERROR=ON
      - name: Configure Clang
        run: >
          cmake -G Ninja -S . -B .
          -DPYBIND11_WERROR=OFF
          -DPYBIND11_SIMPLE_GIL_MANAGEMENT=OFF
          -DDOWNLOAD_CATCH=ON
          -DDOWNLOAD_EIGEN=ON
          -DCMAKE_CXX_COMPILER=clang++
          -DCMAKE_CXX_STANDARD=17

      - name: Build
        run: cmake --build . -j 2

      - name: Python tests
        run: cmake --build . --target pytest -j 2

      - name: C++ tests
        timeout-minutes: 3
        run: cmake --build . --target cpptest -j 2

      - name: Interface test
        run: cmake --build . --target test_cmake_build -j 2

      - name: Visibility test
        run: cmake --build . --target test_cross_module_rtti -j 2

      - name: Clean directory
        run: git clean -fdx

  # Clang with MSVC/Windows SDK toolchain + python.org CPython (Windows ARM)
  windows_arm_clang_msvc:
    if: github.event.pull_request.draft == false

    strategy:
      fail-fast: false
      matrix:
        os: [windows-11-arm]
        python: ['3.13']

    runs-on: "${{ matrix.os }}"
    timeout-minutes: 90

    name: "🐍 ${{ matrix.python }} • ${{ matrix.os }} • clang-msvc"

    steps:
      - name: Show env
        run: env

      - name: Checkout
        uses: actions/checkout@v7

      - name: Setup Python ${{ matrix.python }}
        uses: actions/setup-python@v7
        with:
          python-version: ${{ matrix.python }}
          architecture: arm64

      - name: Run pip installs
        run: |
          python -m pip install --upgrade pip
          python -m pip install -r tests/requirements.txt

      - name: Configure CMake
        run: |
          $pythonExecutable = Join-Path $env:pythonLocation "python.exe"
          $pythonIncludeDir = Join-Path $env:pythonLocation "include"
          $pythonVersion = (python -c "import sys; print(f'{sys.version_info.major}{sys.version_info.minor}')").Trim()
          # PR 6051: FindPython can still resolve the x64 python.org install on
          # windows-11-arm, so pass the ARM64 interpreter, headers, and import lib.
          $pythonLibrary = Join-Path (Join-Path $env:pythonLocation "libs") "python$pythonVersion.lib"
          cmake -G Ninja -S . -B . `
            -DPYBIND11_WERROR=OFF `
            -DPYBIND11_SIMPLE_GIL_MANAGEMENT=OFF `
            -DDOWNLOAD_CATCH=ON `
            -DDOWNLOAD_EIGEN=ON `
            -DCMAKE_CXX_COMPILER=clang++ `
            -DCMAKE_CXX_STANDARD=20 `
            -DPython_EXECUTABLE="$pythonExecutable" `
            -DPython_INCLUDE_DIR="$pythonIncludeDir" `
            -DPython_LIBRARY="$pythonLibrary"

      - name: Build
        run: cmake --build . -j 2

      - name: Python tests
        run: cmake --build . --target pytest -j 2

      - name: C++ tests
        timeout-minutes: 3
        run: cmake --build . --target cpptest -j 2

      - name: Interface test
        run: cmake --build . --target test_cmake_build -j 2

      - name: Visibility test
        run: cmake --build . --target test_cross_module_rtti -j 2

  # Clang in MSYS2/MinGW-w64 CLANGARM64 toolchain + MSYS2 Python (Windows ARM)
  windows_arm_clang_msys2:
    if: github.event.pull_request.draft == false

    strategy:
      fail-fast: false
      matrix:
        os: [windows-11-arm]

    runs-on: "${{ matrix.os }}"
    timeout-minutes: 90

    name: "${{ matrix.os }} • clang-msys2"

    defaults:
      run:
        shell: msys2 {0}

    steps:
    - uses: actions/checkout@v7
      with:
        submodules: true

    - uses: msys2/setup-msys2@v2
      with:
        msystem: CLANGARM64
        update: true
        install: |
          mingw-w64-clang-aarch64-cmake
          mingw-w64-clang-aarch64-clang
          mingw-w64-clang-aarch64-ninja
          mingw-w64-clang-aarch64-python-pip
          mingw-w64-clang-aarch64-python-pytest
          mingw-w64-clang-aarch64-python-numpy

    - name: Debug info
      run: |
        clang++ --version
        cmake --version
        ninja --version
        python --version

    - name: Run pip installs
      run: |
        python -m pip install --upgrade pip
        python -m pip install -r tests/requirements.txt

    - name: Configure CMake
      run: >-
        cmake -S . -B build
        -DPYBIND11_WERROR=OFF
        -DDOWNLOAD_CATCH=ON
        -DDOWNLOAD_EIGEN=ON
        -DCMAKE_CXX_COMPILER=clang++
        -DCMAKE_CXX_STANDARD=20
        -DPYTHON_EXECUTABLE=$(python -c "import sys; print(sys.executable)")

    - name: Build
      run: cmake --build build -j 2

    - name: Python tests
      run: cmake --build build --target pytest -j 2

    - name: C++ tests
      timeout-minutes: 3
      run: PYTHONHOME=/clangarm64 PYTHONPATH=/clangarm64 cmake --build build --target cpptest -j 2

    - name: Interface test
      run: cmake --build build --target test_cmake_build -j 2

    - name: Visibility test
      run: cmake --build build --target test_cross_module_rtti -j 2