diff --git a/.github/actions/dynamatrix/action.yml b/.github/actions/dynamatrix/action.yml
new file mode 100644
index 00000000..11eef3bb
--- /dev/null
+++ b/.github/actions/dynamatrix/action.yml
@@ -0,0 +1,22 @@
+name: Create matrix
+description: Create matrix
+inputs:
+  matrix_yaml:
+    description: input yaml matrix as multiline string; any entry with a bool true `omit` key will be filtered from the output matrix
+    required: true
+outputs:
+  matrix_json:
+    description: filtered matrix as JSON
+    value: ${{ steps.matrix_gen.outputs.matrix_json }}
+
+runs:
+  using: "composite"
+
+  steps:
+    - id: matrix_gen
+      run: |
+        # FIXME: input sanity check to prevent shell injection
+        python3 $GITHUB_ACTION_PATH/matrix_yaml_to_json.py --from-stdin << EOF
+        ${{ inputs.matrix_yaml }}
+        EOF
+      shell: bash
diff --git a/.github/actions/dynamatrix/matrix_yaml_to_json.py b/.github/actions/dynamatrix/matrix_yaml_to_json.py
new file mode 100644
index 00000000..f6f7e776
--- /dev/null
+++ b/.github/actions/dynamatrix/matrix_yaml_to_json.py
@@ -0,0 +1,71 @@
+from __future__ import annotations
+
+import argparse
+import json
+import os
+import pathlib
+import sys
+import typing as t
+import yaml
+
+from collections.abc import MutableMapping, Sequence
+
+skipped_entries = []
+
+def _filter_omit_entries(value):
+    if isinstance(value, MutableMapping):
+        if (omit_value := value.pop('omit', ...)) is not ...:
+            if omit_value is True:
+                print(f'omitting {value} from matrix')
+                skipped_entries.append(value)
+                return ...
+
+        return {k: v for k, v in ((k, _filter_omit_entries(v)) for k, v in value.items()) if v is not ...}
+
+    if isinstance(value, str):
+        return value
+
+    if isinstance(value, Sequence):
+        return [v for v in (_filter_omit_entries(v) for v in value) if v is not ...]
+
+    return value
+
+def main():
+    p = argparse.ArgumentParser(description='GHA YAML matrix filter')
+    required_grp = p.add_mutually_exclusive_group(required=True)
+    required_grp.add_argument('--from-stdin', action='store_true', help='read input YAML from stdin')
+    required_grp.add_argument('--from-file', type=pathlib.Path, help='read input YAML from file path')
+
+    args = p.parse_args()
+
+    path: pathlib.Path | None
+
+    matrix_yaml: str
+
+    if path := args.from_file:
+        matrix_yaml = path.read_text()
+    elif args.from_stdin:
+        matrix_yaml = sys.stdin.read()
+    else:
+        raise Exception('no source provided for matrix yaml')
+
+    raw_matrix = yaml.safe_load(matrix_yaml)
+    filtered_matrix = _filter_omit_entries(raw_matrix)
+
+    output_matrix_json = json.dumps(filtered_matrix)
+    output_skipped_matrix_json = json.dumps(skipped_entries)
+
+    print(f'filtered matrix: {output_matrix_json}')
+    print(f'skipped entries: {output_skipped_matrix_json}')
+
+    if (gh_output := os.environ.get('GITHUB_OUTPUT')):
+        print('setting step output var matrix_json; skipped_matrix_json...')
+        with pathlib.Path(gh_output).open('a') as env_fd:
+            env_fd.write(f'matrix_json<<__MATRIX_EOF\n{output_matrix_json}\n__MATRIX_EOF\n')
+            env_fd.write(f'skipped_matrix_json<<__MATRIX_EOF\n{output_skipped_matrix_json}\n__MATRIX_EOF\n')
+    else:
+        print("GITHUB_OUTPUT not set; skipping variable output")
+
+
+if __name__ == '__main__':
+    main()
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 783f0800..027a355a 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -10,57 +10,60 @@ on:
 env:
   LIBYAML_REPO: https://github.com/yaml/libyaml
   LIBYAML_REF: 0.2.5
+  skip_ci_redundant_jobs: ${{ github.event_name == 'pull_request' }}
+  skip_slow_jobs: ${{ github.event_name == 'pull_request' }}
+  skip_artifact_upload: ${{ github.event_name == 'pull_request' }}
 
 jobs:
-  python_sdist:
-    name: pyyaml sdist
-    runs-on: ubuntu-22.04
-    steps:
-    - name: Checkout PyYAML
-      uses: actions/checkout@v3
-
-    - name: Install a python
-      uses: actions/setup-python@v4
-      with:
-        python-version: 3.x
-
-    - name: Build sdist
-      env:
-        PYYAML_FORCE_CYTHON: 1
-        PYYAML_FORCE_LIBYAML: 0
-      run: |
-        python -V
-        python -m pip install build
-
-        python -m build .
-
-        # Ensure exactly one artifact was produced.
-        [[ $(shopt -s nullglob; ls dist/*.tar.gz | wc -w) == 1 ]] || {
-          echo "Unexpected content in dist dir: '$(ls dist/*.tar.gz)'."
-          exit 1
-        }
-
-    - name: Test sdist
-      run: |
-        # Install some libyaml headers.
-        # TODO Should we smoke test the sdist against the libyaml we built?
-        sudo apt update
-        sudo apt install libyaml-dev -y
-
-        # Ensure Cython is not present so we use only what's in the sdist.
-        python -m pip uninstall Cython -y || true
-
-        # Pass no extra args.
-        # We should auto-install with libyaml since it's present.
-        python -m pip install dist/*.tar.gz -v
-
-        python packaging/build/smoketest.py
-
-    - name: Upload sdist artifact
-      uses: actions/upload-artifact@v3
-      with:
-        name: dist
-        path: dist/*.tar.gz
+#  python_sdist:
+#    name: pyyaml sdist
+#    runs-on: ubuntu-22.04
+#    steps:
+#    - name: Checkout PyYAML
+#      uses: actions/checkout@v3
+#
+#    - name: Install a python
+#      uses: actions/setup-python@v4
+#      with:
+#        python-version: 3.x
+#
+#    - name: Build sdist
+#      env:
+#        PYYAML_FORCE_CYTHON: 1
+#        PYYAML_FORCE_LIBYAML: 0
+#      run: |
+#        python -V
+#        python -m pip install build
+#
+#        python -m build .
+#
+#        # Ensure exactly one artifact was produced.
+#        [[ $(shopt -s nullglob; ls dist/*.tar.gz | wc -w) == 1 ]] || {
+#          echo "Unexpected content in dist dir: '$(ls dist/*.tar.gz)'."
+#          exit 1
+#        }
+#
+#    - name: Test sdist
+#      run: |
+#        # Install some libyaml headers.
+#        # TODO Should we smoke test the sdist against the libyaml we built?
+#        sudo apt update
+#        sudo apt install libyaml-dev -y
+#
+#        # Ensure Cython is not present so we use only what's in the sdist.
+#        python -m pip uninstall Cython -y || true
+#
+#        # Pass no extra args.
+#        # We should auto-install with libyaml since it's present.
+#        python -m pip install dist/*.tar.gz -v
+#
+#        python packaging/build/smoketest.py
+#
+#    - name: Upload sdist artifact
+#      uses: actions/upload-artifact@v3
+#      with:
+#        name: dist
+#        path: dist/*.tar.gz
 
 
   linux_libyaml:
@@ -69,12 +72,10 @@ jobs:
     strategy:
       matrix:
         cfg:
-#        - { platform: manylinux1, arch: x86_64 }
+        - { platform: manylinux1, arch: x86_64 }
         - { platform: manylinux2014, arch: x86_64 }
         - { platform: manylinux2014, arch: aarch64 }
         - { platform: manylinux2014, arch: s390x }
-#        - { platform: manylinux2_28, arch: x86_64 }
-#        - { platform: manylinux2_28, arch: aarch64 }
         - { platform: musllinux_1_1, arch: x86_64 }
     env:
       DOCKER_IMAGE: quay.io/pypa/${{matrix.cfg.platform}}_${{matrix.cfg.arch}}
@@ -110,38 +111,51 @@ jobs:
         sudo chmod -R a+r ./libyaml/
       if: steps.cached_libyaml.outputs.cache-hit != 'true'
 
+  make_linux_pyyaml_matrix:
+    runs-on: ubuntu-22.04
+    outputs:
+      matrix_json: ${{ steps.make_matrix.outputs.matrix_json }}
+    steps:
+    - uses: actions/checkout@v4
+    - name: make a matrix
+      id: make_matrix
+      uses: ./.github/actions/dynamatrix
+      with:
+        matrix_yaml: |
+          include:
+          - { platform: manylinux1, arch: x86_64, spec: cp38, omit: ${{ env.skip_ci_redundant_jobs }} }
+          - { platform: manylinux1, arch: x86_64, spec: cp39, omit: ${{ env.skip_ci_redundant_jobs }} }
+          - { platform: manylinux2014, arch: x86_64, spec: cp310, omit: ${{ env.skip_ci_redundant_jobs }} }
+          - { platform: manylinux2014, arch: x86_64, spec: cp311, omit: ${{ env.skip_ci_redundant_jobs }} }
+          - { platform: manylinux2014, arch: x86_64, spec: cp312, omit: ${{ env.skip_ci_redundant_jobs }} }
+          - { platform: manylinux2014, arch: aarch64, spec: cp313, cibw_version: "https://github.com/nitzmahone/cibuildwheel/archive/refs/heads/py313_support.zip", omit: ${{ env.skip_slow_jobs }} }
+          - { platform: manylinux2014, arch: aarch64, spec: cp38, omit: ${{ env.skip_ci_redundant_jobs || env.skip_slow_jobs }} }
+          - { platform: manylinux2014, arch: aarch64, spec: cp39, omit: ${{ env.skip_ci_redundant_jobs || env.skip_slow_jobs }} }
+          - { platform: manylinux2014, arch: aarch64, spec: cp310, omit: ${{ env.skip_ci_redundant_jobs || env.skip_slow_jobs }} }
+          - { platform: manylinux2014, arch: aarch64, spec: cp311, omit: ${{ env.skip_ci_redundant_jobs || env.skip_slow_jobs }} }
+          - { platform: manylinux2014, arch: aarch64, spec: cp312, omit: ${{ env.skip_ci_redundant_jobs || env.skip_slow_jobs }} }
+          - { platform: manylinux2014, arch: aarch64, spec: cp313, cibw_version: "https://github.com/nitzmahone/cibuildwheel/archive/refs/heads/py313_support.zip", omit: ${{ env.skip_slow_jobs }} }
+          - { platform: manylinux2014, arch: s390x, spec: cp38, omit: ${{ env.skip_ci_redundant_jobs || env.skip_slow_jobs }} }
+          - { platform: manylinux2014, arch: s390x, spec: cp39, omit: ${{ env.skip_ci_redundant_jobs || env.skip_slow_jobs }} }
+          - { platform: manylinux2014, arch: s390x, spec: cp310, omit: ${{ env.skip_ci_redundant_jobs || env.skip_slow_jobs }} }
+          - { platform: manylinux2014, arch: s390x, spec: cp311, omit: ${{ env.skip_ci_redundant_jobs || env.skip_slow_jobs }} }
+          - { platform: manylinux2014, arch: s390x, spec: cp312, omit: ${{ env.skip_ci_redundant_jobs || env.skip_slow_jobs }} }
+          - { platform: manylinux2014, arch: s390x, spec: cp313, cibw_version: "https://github.com/nitzmahone/cibuildwheel/archive/refs/heads/py313_support.zip", omit: ${{ env.skip_ci_redundant_jobs || env.skip_slow_jobs }} }
+          - { platform: musllinux_1_1, arch: x86_64, spec: cp38, omit: ${{ env.skip_ci_redundant_jobs || env.skip_slow_jobs }} }
+          - { platform: musllinux_1_1, arch: x86_64, spec: cp39, omit: ${{ env.skip_ci_redundant_jobs || env.skip_slow_jobs }} }
+          - { platform: musllinux_1_1, arch: x86_64, spec: cp310, omit: ${{ env.skip_ci_redundant_jobs || env.skip_slow_jobs }} }
+          - { platform: musllinux_1_1, arch: x86_64, spec: cp311, omit: ${{ env.skip_ci_redundant_jobs || env.skip_slow_jobs }} }
+          - { platform: musllinux_1_1, arch: x86_64, spec: cp312, omit: ${{ env.skip_ci_redundant_jobs || env.skip_slow_jobs }} }
+          - { platform: musllinux_1_1, arch: x86_64, spec: cp313, cibw_version: "https://github.com/nitzmahone/cibuildwheel/archive/refs/heads/py313_support.zip", omit: ${{ env.skip_ci_redundant_jobs || env.skip_slow_jobs }} }
+
 
   linux_pyyaml:
-    needs: linux_libyaml
+    needs: [linux_libyaml, make_linux_pyyaml_matrix]
     name: pyyaml ${{matrix.arch}} ${{matrix.platform}} ${{matrix.spec}}
     runs-on: ubuntu-22.04
     strategy:
-      matrix:
-        include:
-#        - { platform: manylinux1, arch: x86_64, spec: cp38 }
-#        - { platform: manylinux1, arch: x86_64, spec: cp39 }
-#        - { platform: manylinux2014, arch: x86_64, spec: cp310 }
-#        - { platform: manylinux2014, arch: x86_64, spec: cp311 }
-#        - { platform: manylinux2014, arch: x86_64, spec: cp312 }
-        - { platform: manylinux2014, arch: aarch64, spec: cp313, cibw_version: "https://github.com/nitzmahone/cibuildwheel/archive/refs/heads/py313_support.zip" }
-#        - { platform: manylinux2014, arch: aarch64, spec: cp38 }
-#        - { platform: manylinux2014, arch: aarch64, spec: cp39 }
-#        - { platform: manylinux2014, arch: aarch64, spec: cp310 }
-#        - { platform: manylinux2014, arch: aarch64, spec: cp311 }
-#        - { platform: manylinux2014, arch: aarch64, spec: cp312 }
-        - { platform: manylinux2014, arch: aarch64, spec: cp313, cibw_version: "https://github.com/nitzmahone/cibuildwheel/archive/refs/heads/py313_support.zip" }
-#        - { platform: manylinux2014, arch: s390x, spec: cp38 }
-#        - { platform: manylinux2014, arch: s390x, spec: cp39 }
-#        - { platform: manylinux2014, arch: s390x, spec: cp310 }
-#        - { platform: manylinux2014, arch: s390x, spec: cp311 }
-#        - { platform: manylinux2014, arch: s390x, spec: cp312 }
-        - { platform: manylinux2014, arch: s390x, spec: cp313, cibw_version: "https://github.com/nitzmahone/cibuildwheel/archive/refs/heads/py313_support.zip" }
-#        - { platform: musllinux_1_1, arch: x86_64, spec: cp38 }
-#        - { platform: musllinux_1_1, arch: x86_64, spec: cp39 }
-#        - { platform: musllinux_1_1, arch: x86_64, spec: cp310 }
-#        - { platform: musllinux_1_1, arch: x86_64, spec: cp311 }
-#        - { platform: musllinux_1_1, arch: x86_64, spec: cp312 }
-        - { platform: musllinux_1_1, arch: x86_64, spec: cp313, cibw_version: "https://github.com/nitzmahone/cibuildwheel/archive/refs/heads/py313_support.zip" }
+      fail-fast: false
+      matrix: ${{ fromJSON(needs.make_linux_matrix.outputs.matrix_json) }}
 
     steps:
     - name: Checkout PyYAML
@@ -186,278 +200,291 @@ jobs:
         name: dist
         path: dist/*.whl
         if-no-files-found: error
-
-  macos_libyaml:
-    name: libyaml macos ${{matrix.arch}}
-    strategy:
-      matrix:
-        include:
-        - arch: x86_64
-          runs-on: macos-13
-        - arch: arm64
-          deployment_target: '11.0'
-          run_wrapper: arch -arm64 bash --noprofile --norc -eo pipefail {0}
-    defaults:
-      run:
-        shell: ${{ matrix.run_wrapper || 'bash --noprofile --norc -eo pipefail {0}' }}
-    runs-on: ${{ matrix.runs_on || 'macos-14' }}
-    steps:
-    - name: Check cached libyaml state
-      id: cached_libyaml
-      uses: actions/cache@v3
-      with:
-        path: libyaml
-        key: libyaml_macos_${{matrix.arch}}_${{env.LIBYAML_REF}}
-
-    - name: Checkout PyYAML
-      uses: actions/checkout@v3
-      if: steps.cached_libyaml.outputs.cache-hit != 'true'
-
-    - name: Build libyaml
-      env:
-        MACOSX_DEPLOYMENT_TARGET: ${{ matrix.deployment_target || '10.9' }}
-        SDKROOT: ${{ matrix.sdkroot || 'macosx' }}
-      run: |
-        set -eux
-        brew install automake coreutils m4
-        bash ./packaging/build/libyaml.sh
-        echo "finished artifact arch is $(lipo -archs libyaml/src/.libs/libyaml.a)"
-      if: steps.cached_libyaml.outputs.cache-hit != 'true'
-
-
-  macos_pyyaml:
-    needs: macos_libyaml
-    name: pyyaml ${{ matrix.spec }}
-    runs-on: ${{ matrix.runs_on || 'macos-14' }}
-    defaults:
-      run:
-        shell: ${{ matrix.run_wrapper || 'bash --noprofile --norc -eo pipefail {0}' }}
-    strategy:
-      matrix:
-        include:
-        - spec: cp38-macosx_x86_64
-          cibw_version: cibuildwheel==2.11.1
-          runs_on: [macos-13]
-        - spec: cp39-macosx_x86_64
-          runs_on: [macos-13]
-#        - spec: cp310-macosx_x86_64
+#
+#  macos_libyaml:
+#    name: libyaml macos ${{matrix.arch}}
+#    strategy:
+#      matrix:
+#        include:
+#        - arch: x86_64
+#          runs-on: macos-13
+#        - arch: arm64
+#          deployment_target: '11.0'
+#          run_wrapper: arch -arm64 bash --noprofile --norc -eo pipefail {0}
+#    defaults:
+#      run:
+#        shell: ${{ matrix.run_wrapper || 'bash --noprofile --norc -eo pipefail {0}' }}
+#    runs-on: ${{ matrix.runs_on || 'macos-14' }}
+#    steps:
+#    - name: Check cached libyaml state
+#      id: cached_libyaml
+#      uses: actions/cache@v3
+#      with:
+#        path: libyaml
+#        key: libyaml_macos_${{matrix.arch}}_${{env.LIBYAML_REF}}
+#
+#    - name: Checkout PyYAML
+#      uses: actions/checkout@v3
+#      if: steps.cached_libyaml.outputs.cache-hit != 'true'
+#
+#    - name: Build libyaml
+#      env:
+#        MACOSX_DEPLOYMENT_TARGET: ${{ matrix.deployment_target || '10.9' }}
+#        SDKROOT: ${{ matrix.sdkroot || 'macosx' }}
+#      run: |
+#        set -eux
+#        brew install automake coreutils m4
+#        bash ./packaging/build/libyaml.sh
+#        echo "finished artifact arch is $(lipo -archs libyaml/src/.libs/libyaml.a)"
+#      if: steps.cached_libyaml.outputs.cache-hit != 'true'
+#
+#
+#  macos_pyyaml:
+#    needs: macos_libyaml
+#    name: pyyaml ${{ matrix.spec }}
+#    runs-on: ${{ matrix.runs_on || 'macos-14' }}
+#    defaults:
+#      run:
+#        shell: ${{ matrix.run_wrapper || 'bash --noprofile --norc -eo pipefail {0}' }}
+#    strategy:
+#      matrix:
+#        include:
+#        - spec: cp38-macosx_x86_64
+#          cibw_version: cibuildwheel==2.11.1
 #          runs_on: [macos-13]
-#        - spec: cp311-macosx_x86_64
+#        - spec: cp39-macosx_x86_64
 #          runs_on: [macos-13]
-#        - spec: cp312-macosx_x86_64
+##        - spec: cp310-macosx_x86_64
+##          runs_on: [macos-13]
+##        - spec: cp311-macosx_x86_64
+##          runs_on: [macos-13]
+##        - spec: cp312-macosx_x86_64
+##          runs_on: [macos-13]
+#        - spec: cp313-macosx_x86_64
+#          cibw_version: https://github.com/nitzmahone/cibuildwheel/archive/refs/heads/py313_support.zip
 #          runs_on: [macos-13]
-        - spec: cp313-macosx_x86_64
-          cibw_version: https://github.com/nitzmahone/cibuildwheel/archive/refs/heads/py313_support.zip
-          runs_on: [macos-13]
-
-        # build for arm64 under a hacked macOS 12 self-hosted x86_64-on-arm64 runner until arm64 is fully supported
-        - spec: cp39-macosx_arm64
-          deployment_target: '11.0'
-          arch: arm64
-          run_wrapper: arch -arm64 bash --noprofile --norc -eo pipefail {0}
-
-        - spec: cp310-macosx_arm64
-          deployment_target: '11.0'
-          arch: arm64
-          run_wrapper: arch -arm64 bash --noprofile --norc -eo pipefail {0}
-
-        - spec: cp311-macosx_arm64
-          deployment_target: '11.0'
-          arch: arm64
-          run_wrapper: arch -arm64 bash --noprofile --norc -eo pipefail {0}
-
-        - spec: cp312-macosx_arm64
-          deployment_target: '11.0'
-          arch: arm64
-          run_wrapper: arch -arm64 bash --noprofile --norc -eo pipefail {0}
-
-        - spec: cp313-macosx_arm64
-          deployment_target: '11.0'
-          arch: arm64
-          run_wrapper: arch -arm64 bash --noprofile --norc -eo pipefail {0}
-          cibw_version: https://github.com/nitzmahone/cibuildwheel/archive/refs/heads/py313_support.zip
-
-    steps:
-    - name: Checkout PyYAML
-      uses: actions/checkout@v3
-
-    - name: Get cached libyaml state
-      id: cached_libyaml
-      uses: actions/cache/restore@v3
-      with:
-        path: libyaml
-        key: libyaml_macos_${{ matrix.arch || 'x86_64' }}_${{env.LIBYAML_REF}}
-        fail-on-cache-miss: true
-
-    - name: Build/Test/Package
-      env:
-        C_INCLUDE_PATH: libyaml/include
-        CIBW_BUILD: ${{matrix.spec}}
-        CIBW_BUILD_VERBOSITY: 1
-        CIBW_TEST_COMMAND: cd {project}; pytest
-        CIBW_TEST_REQUIRES: pytest
-        LIBRARY_PATH: libyaml/src/.libs
-        MACOSX_DEPLOYMENT_TARGET: ${{ matrix.deployment_target || '10.9' }}
-        PYYAML_FORCE_CYTHON: 1
-        PYYAML_FORCE_LIBYAML: 1
-        SDKROOT: ${{ matrix.sdkroot || 'macosx' }}
-      run: |
-        python3 -V
-        python3 -m pip install -U --user ${{ matrix.cibw_version || 'cibuildwheel' }}
-        python3 -m cibuildwheel --platform auto --output-dir dist .
-
-    - name: Upload artifacts
-      uses: actions/upload-artifact@v3
-      with:
-        name: dist
-        path: dist/*.whl
-        if-no-files-found: error
-
-  windows_libyaml:
-    name: libyaml ${{matrix.platform}} ${{matrix.arch}}
-    runs-on: ${{matrix.platform}}
-    strategy:
-      matrix:
-        include:
-        - platform: windows-2022
-          arch: x64
-        - platform: windows-2022
-          arch: win32
-    steps:
-    - name: Get cached libyaml state
-      id: cached_libyaml
-      uses: actions/cache@v3
-      with:
-        path: libyaml
-        key: libyaml_${{matrix.platform}}_${{matrix.arch}}_${{env.LIBYAML_REF}}
-
-    - name: Build libyaml
-      shell: bash
-      if: steps.cached_libyaml.outputs.cache-hit != 'true'
-      run: |
-        # git spews all over stderr unless we tell it not to
-        export GIT_REDIRECT_STDERR="2>&1"
-
-        if [[ ! -d ./libyaml ]]; then
-          git clone -b ${{ env.LIBYAML_REF }} ${{ env.LIBYAML_REPO }} 2>&1
-        fi
-
-        pushd libyaml
-        git clean -fdx
-        popd
-
-        mkdir libyaml/build
-
-        pushd libyaml/build
-        cmake.exe -G "Visual Studio 16 2019" -A ${{ matrix.arch }} -DYAML_STATIC_LIB_NAME=yaml ..
-        cmake.exe --build . --config Release
-        popd
-
-
-  windows_pyyaml:
-    needs: windows_libyaml
-    name: pyyaml ${{ matrix.platform }} ${{matrix.python_arch}} ${{matrix.spec}}
-    runs-on: ${{matrix.platform}}
-    strategy:
-      matrix:
-        include:
-        - platform: windows-2022
-          build_arch: x64
-          python_arch: x64
-          spec: 3.8
+#
+#        # build for arm64 under a hacked macOS 12 self-hosted x86_64-on-arm64 runner until arm64 is fully supported
+#        - spec: cp39-macosx_arm64
+#          deployment_target: '11.0'
+#          arch: arm64
+#          run_wrapper: arch -arm64 bash --noprofile --norc -eo pipefail {0}
+#
+#        - spec: cp310-macosx_arm64
+#          deployment_target: '11.0'
+#          arch: arm64
+#          run_wrapper: arch -arm64 bash --noprofile --norc -eo pipefail {0}
+#
+#        - spec: cp311-macosx_arm64
+#          deployment_target: '11.0'
+#          arch: arm64
+#          run_wrapper: arch -arm64 bash --noprofile --norc -eo pipefail {0}
+#
+#        - spec: cp312-macosx_arm64
+#          deployment_target: '11.0'
+#          arch: arm64
+#          run_wrapper: arch -arm64 bash --noprofile --norc -eo pipefail {0}
+#
+#        - spec: cp313-macosx_arm64
+#          deployment_target: '11.0'
+#          arch: arm64
+#          run_wrapper: arch -arm64 bash --noprofile --norc -eo pipefail {0}
+#          cibw_version: https://github.com/nitzmahone/cibuildwheel/archive/refs/heads/py313_support.zip
+#
+#    steps:
+#    - name: Checkout PyYAML
+#      uses: actions/checkout@v3
+#
+#    - name: Get cached libyaml state
+#      id: cached_libyaml
+#      uses: actions/cache/restore@v3
+#      with:
+#        path: libyaml
+#        key: libyaml_macos_${{ matrix.arch || 'x86_64' }}_${{env.LIBYAML_REF}}
+#        fail-on-cache-miss: true
+#
+#    - name: Build/Test/Package
+#      env:
+#        C_INCLUDE_PATH: libyaml/include
+#        CIBW_BUILD: ${{matrix.spec}}
+#        CIBW_BUILD_VERBOSITY: 1
+#        CIBW_TEST_COMMAND: cd {project}; pytest
+#        CIBW_TEST_REQUIRES: pytest
+#        LIBRARY_PATH: libyaml/src/.libs
+#        MACOSX_DEPLOYMENT_TARGET: ${{ matrix.deployment_target || '10.9' }}
+#        PYYAML_FORCE_CYTHON: 1
+#        PYYAML_FORCE_LIBYAML: 1
+#        SDKROOT: ${{ matrix.sdkroot || 'macosx' }}
+#      run: |
+#        python3 -V
+#        python3 -m pip install -U --user ${{ matrix.cibw_version || 'cibuildwheel' }}
+#        python3 -m cibuildwheel --platform auto --output-dir dist .
+#
+#    - name: Upload artifacts
+#      uses: actions/upload-artifact@v3
+#      with:
+#        name: dist
+#        path: dist/*.whl
+#        if-no-files-found: error
+#
+#  windows_libyaml:
+#    name: libyaml ${{matrix.platform}} ${{matrix.arch}}
+#    runs-on: ${{matrix.platform}}
+#    strategy:
+#      matrix:
+#        include:
 #        - platform: windows-2022
-#          build_arch: x64
-#          python_arch: x64
-#          spec: 3.9
+#          arch: x64
 #        - platform: windows-2022
-#          build_arch: x64
-#          python_arch: x64
-#          spec: '3.10'
+#          arch: win32
+#    steps:
+#    - name: Get cached libyaml state
+#      id: cached_libyaml
+#      uses: actions/cache@v3
+#      with:
+#        path: libyaml
+#        key: libyaml_${{matrix.platform}}_${{matrix.arch}}_${{env.LIBYAML_REF}}
+#
+#    - name: Build libyaml
+#      shell: bash
+#      if: steps.cached_libyaml.outputs.cache-hit != 'true'
+#      run: |
+#        # git spews all over stderr unless we tell it not to
+#        export GIT_REDIRECT_STDERR="2>&1"
+#
+#        if [[ ! -d ./libyaml ]]; then
+#          git clone -b ${{ env.LIBYAML_REF }} ${{ env.LIBYAML_REPO }} 2>&1
+#        fi
+#
+#        pushd libyaml
+#        git clean -fdx
+#        popd
+#
+#        mkdir libyaml/build
+#
+#        pushd libyaml/build
+#        cmake.exe -G "Visual Studio 16 2019" -A ${{ matrix.arch }} -DYAML_STATIC_LIB_NAME=yaml ..
+#        cmake.exe --build . --config Release
+#        popd
+#
+#
+#  windows_pyyaml:
+#    needs: windows_libyaml
+#    name: pyyaml ${{ matrix.platform }} ${{matrix.python_arch}} ${{matrix.spec}}
+#    runs-on: ${{matrix.platform}}
+#    strategy:
+#      matrix:
+#        include:
 #        - platform: windows-2022
 #          build_arch: x64
 #          python_arch: x64
-#          spec: '3.11'
+#          spec: 3.8
+##        - platform: windows-2022
+##          build_arch: x64
+##          python_arch: x64
+##          spec: 3.9
+##        - platform: windows-2022
+##          build_arch: x64
+##          python_arch: x64
+##          spec: '3.10'
+##        - platform: windows-2022
+##          build_arch: x64
+##          python_arch: x64
+##          spec: '3.11'
+##        - platform: windows-2022
+##          build_arch: x64
+##          python_arch: x64
+##          spec: '3.12'
 #        - platform: windows-2022
 #          build_arch: x64
 #          python_arch: x64
-#          spec: '3.12'
-        - platform: windows-2022
-          build_arch: x64
-          python_arch: x64
-          spec: '3.13'
-        - platform: windows-2022
-          build_arch: win32
-          python_arch: x86
-          spec: 3.8
+#          spec: '3.13'
 #        - platform: windows-2022
 #          build_arch: win32
 #          python_arch: x86
-#          spec: 3.9
+#          spec: 3.8
+##        - platform: windows-2022
+##          build_arch: win32
+##          python_arch: x86
+##          spec: 3.9
+##        - platform: windows-2022
+##          build_arch: win32
+##          python_arch: x86
+##          spec: '3.10'
+##        - platform: windows-2022
+##          build_arch: win32
+##          python_arch: x86
+##          spec: '3.11'
+##        - platform: windows-2022
+##          build_arch: win32
+##          python_arch: x86
+##          spec: '3.12'
 #        - platform: windows-2022
 #          build_arch: win32
 #          python_arch: x86
-#          spec: '3.10'
-#        - platform: windows-2022
-#          build_arch: win32
-#          python_arch: x86
-#          spec: '3.11'
-#        - platform: windows-2022
-#          build_arch: win32
-#          python_arch: x86
-#          spec: '3.12'
-        - platform: windows-2022
-          build_arch: win32
-          python_arch: x86
-          spec: '3.13'
-    steps:
-    # autocrlf screws up tests under Windows
-    - name: Set git to use LF
-      run: |
-        git config --global core.autocrlf false
-        git config --global core.eol lf
-
-    - name: Checkout pyyaml
-      uses: actions/checkout@v3
-
-    - name: Get cached libyaml state
-      id: cached_libyaml
-      uses: actions/cache/restore@v3
-      with:
-        path: libyaml
-        key: libyaml_${{matrix.platform}}_${{matrix.build_arch}}_${{env.LIBYAML_REF}}
-        fail-on-cache-miss: true
-
-    - name: Install python ${{ matrix.spec }}
-      uses: actions/setup-python@v4
-      with:
-        architecture: ${{ matrix.python_arch }}
-        python-version: ${{ matrix.spec }}
-
-    - name: Build/Test/Package
-      env:
-        PYYAML_FORCE_CYTHON: 1
-        PYYAML_FORCE_LIBYAML: 1
-      shell: bash
-      run: |
-        set -eux
-        python -V
-        python -m pip install "Cython<3.0" setuptools wheel
-
-        python setup.py \
-        --with-libyaml build_ext \
-        -I libyaml/include \
-        -L libyaml/build/Release \
-        -D YAML_DECLARE_STATIC \
-        build bdist_wheel
-
-        # run tests on built wheel
-        python -m pip install dist/*.whl pytest
-        python -I -m pytest
-
-    - name: Upload artifacts
-      uses: actions/upload-artifact@v3
-      with:
-        name: dist
-        path: dist/*.whl
-        if-no-files-found: error
+#          spec: '3.13'
+#    steps:
+#    # autocrlf screws up tests under Windows
+#    - name: Set git to use LF
+#      run: |
+#        git config --global core.autocrlf false
+#        git config --global core.eol lf
+#
+#    - name: Checkout pyyaml
+#      uses: actions/checkout@v3
+#
+#    - name: Get cached libyaml state
+#      id: cached_libyaml
+#      uses: actions/cache/restore@v3
+#      with:
+#        path: libyaml
+#        key: libyaml_${{matrix.platform}}_${{matrix.build_arch}}_${{env.LIBYAML_REF}}
+#        fail-on-cache-miss: true
+#
+#    - name: Install python ${{ matrix.spec }}
+#      uses: actions/setup-python@v4
+#      with:
+#        architecture: ${{ matrix.python_arch }}
+#        python-version: ${{ matrix.spec }}
+#
+#    - name: Build/Test/Package
+#      env:
+#        PYYAML_FORCE_CYTHON: 1
+#        PYYAML_FORCE_LIBYAML: 1
+#      shell: bash
+#      run: |
+#        set -eux
+#        python -V
+#        python -m pip install "Cython<3.0" setuptools wheel
+#
+#        python setup.py \
+#        --with-libyaml build_ext \
+#        -I libyaml/include \
+#        -L libyaml/build/Release \
+#        -D YAML_DECLARE_STATIC \
+#        build bdist_wheel
+#
+#        # run tests on built wheel
+#        python -m pip install dist/*.whl pytest
+#        python -I -m pytest
+#
+#    - name: Upload artifacts
+#      uses: actions/upload-artifact@v3
+#      with:
+#        name: dist
+#        path: dist/*.whl
+#        if-no-files-found: error
+#  check:
+#    if: always()
+#    needs:
+#    - sdist
+#    - linux
+#    - macos
+#    - windows
+#    runs-on: ubuntu-latest
+#    steps:
+#    - name: Verify all previous jobs succeeded (provides a single check to sample for gating purposes)
+#      uses: re-actors/alls-green@release/v1
+#      with:
+#        jobs: ${{ toJSON(needs) }}
 ...