Build workflow (CalebBell/ht)

The Build workflow from CalebBell/ht, explained and optimized by Latchkey.

CI health: C - fair

Point runs-on at Latchkey and get caching, job timeouts, SHA-pinned actions, self-healing for flaky steps, and up to 58% lower cost, applied automatically.

Grade your own workflow free or run it on Latchkey →

Source: CalebBell/ht.github/workflows/build.ymlLicense MITView source

What it does

This is the Build workflow from the CalebBell/ht repository, a real project running GitHub Actions. It is shown here with attribution under its MIT license.

Below, Latchkey shows a faster, safer version produced by its optimization engine.

The workflow

workflow (.yml)

name: Build

on:
  push:
    branches: [master, release]
  pull_request:
    branches: [master, release]

concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: ${{ github.ref != 'refs/heads/master' && github.ref != 'refs/heads/release' }}

jobs:
  build:

    runs-on: ${{ matrix.os }}
    strategy:
      fail-fast: false
      matrix:
        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13', '3.13t', 'pypy3.11']
        os: [windows-latest, ubuntu-latest, macos-15-intel, macos-latest]
        architecture: ['x86', 'x64']
        exclude:
          # Only test pypy on Linux
          - os: windows-latest
            python-version: pypy3.11
          - os: macos-latest
            python-version: pypy3.11
          - os: macos-15-intel
            python-version: pypy3.11
          # no python builds available on macos 32 bit, arm or x64
          - os: macos-latest
            architecture: x86
          - os: macos-15-intel
            architecture: x86
          # no python builds available on linux 32 bit
          - os: ubuntu-latest
            architecture: x86
          # scipy dropped 32 bit windows builds
          - os: windows-latest
            architecture: x86
            python-version: 3.9
          - os: windows-latest
            architecture: x86
            python-version: 3.10
          - os: windows-latest
            architecture: x86
            python-version: 3.11
          - os: windows-latest
            architecture: x86
            python-version: 3.12
          - os: windows-latest
            architecture: x86
            python-version: 3.13
          - os: windows-latest
            architecture: x86
            python-version: 3.13t
          - os: windows-latest
            architecture: x86
            python-version: 3.14
          # pandas doesn't have wheels for 3.13t on Windows x64
          - os: windows-latest
            architecture: x64
            python-version: 3.13t

          # These are arm - old versions of Python are not supported
          - os: macos-latest
            python-version: 3.9
          - os: macos-latest
            python-version: 3.10
    steps:
    - uses: actions/checkout@v4
    - name: Set up Python ${{ matrix.python-version }} ${{ matrix.architecture }}
      uses: actions/setup-python@v5 
      with:
        python-version: ${{ matrix.python-version }}
        architecture: ${{ matrix.architecture }}

    - name: Install uv
      if: matrix.python-version != '3.13t'
      uses: astral-sh/setup-uv@v4
      with:
        enable-cache: true
        cache-dependency-glob: "pyproject.toml"

    - name: Install Ubuntu dependencies
      if: startsWith(runner.os, 'Linux')
      run: |
        # Taken from scipy
        sudo apt-get update
        sudo apt-get install -y libopenblas-dev libatlas-base-dev liblapack-dev gfortran libgmp-dev libmpfr-dev libsuitesparse-dev ccache libmpc-dev libjpeg-dev zlib1g-dev libtiff-dev libfreetype6-dev liblcms2-dev libwebp-dev

    - name: Install dependencies
      run: |
        python -c "import platform; print(platform.platform()); print(platform.architecture())"
        if [[ "${{ matrix.python-version }}" == "3.13t" ]]; then
          # Use pip for 3.13t (free-threading) as uv may not fully support it yet
          python -m pip install --upgrade pip
          pip install -e .[test]
        else
          uv pip install --system -e .[test]
        fi
      shell: bash
    - name: Add numba
      if: ${{ !contains(fromJSON('["pypy3.11", "3.13t"]'), matrix.python-version) }}
      run: |
        uv pip install --system -e .[numba]
    - name: Test with pytest
      run: |
        pytest . -v --cov-report html --cov=ht --cov-report term-missing -m "not online and not thermo"
        coveralls || true
      env:
        COVERALLS_REPO_TOKEN: ${{ secrets.coveralls }}
        COVERALLS_PARALLEL: true
        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        PYTHON_GIL: ${{ matrix.python-version == '3.13t' && '0' || '' }}

    - name: Upload coverage HTML report
      if: always()
      uses: actions/upload-artifact@v4
      with:
        name: coverage-html-${{ matrix.os }}-${{ matrix.python-version }}-${{ matrix.architecture }}
        path: htmlcov/
  finish:
    needs: build
    runs-on: ubuntu-latest
    steps:
    - name: Coveralls Finished
      env:
        COVERALLS_REPO_TOKEN: ${{ secrets.coveralls }}
        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
      run: |
        curl https://coveralls.io/webhook?repo_token=${{ secrets.coveralls }} -d "payload[build_num]=${{ github.sha }}&payload[status]=done"

The same workflow, on Latchkey

Estimated ~20% faster on cache hits, plus fewer wasted runs and a safer supply chain. Added and changed lines are highlighted.

name: Build
 
on:
  push:
    branches: [master, release]
  pull_request:
    branches: [master, release]
 
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: ${{ github.ref != 'refs/heads/master' && github.ref != 'refs/heads/release' }}
 
jobs:
  build:
    timeout-minutes: 30
 
    runs-on: ${{ matrix.os }}
    strategy:
      fail-fast: false
      matrix:
        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13', '3.13t', 'pypy3.11']
        os: [windows-latest, ubuntu-latest, macos-15-intel, macos-latest]
        architecture: ['x86', 'x64']
        exclude:
          # Only test pypy on Linux
          - os: windows-latest
            python-version: pypy3.11
          - os: macos-latest
            python-version: pypy3.11
          - os: macos-15-intel
            python-version: pypy3.11
          # no python builds available on macos 32 bit, arm or x64
          - os: macos-latest
            architecture: x86
          - os: macos-15-intel
            architecture: x86
          # no python builds available on linux 32 bit
          - os: ubuntu-latest
            architecture: x86
          # scipy dropped 32 bit windows builds
          - os: windows-latest
            architecture: x86
            python-version: 3.9
          - os: windows-latest
            architecture: x86
            python-version: 3.10
          - os: windows-latest
            architecture: x86
            python-version: 3.11
          - os: windows-latest
            architecture: x86
            python-version: 3.12
          - os: windows-latest
            architecture: x86
            python-version: 3.13
          - os: windows-latest
            architecture: x86
            python-version: 3.13t
          - os: windows-latest
            architecture: x86
            python-version: 3.14
          # pandas doesn't have wheels for 3.13t on Windows x64
          - os: windows-latest
            architecture: x64
            python-version: 3.13t
 
          # These are arm - old versions of Python are not supported
          - os: macos-latest
            python-version: 3.9
          - os: macos-latest
            python-version: 3.10
    steps:
    - uses: actions/checkout@v4
    - name: Set up Python ${{ matrix.python-version }} ${{ matrix.architecture }}
      uses: actions/setup-python@v5 
      with:
        cache: 'pip'
        python-version: ${{ matrix.python-version }}
        architecture: ${{ matrix.architecture }}
 
    - name: Install uv
      if: matrix.python-version != '3.13t'
      uses: astral-sh/setup-uv@v4
      with:
        enable-cache: true
        cache-dependency-glob: "pyproject.toml"
 
    - name: Install Ubuntu dependencies
      if: startsWith(runner.os, 'Linux')
      run: |
        # Taken from scipy
        sudo apt-get update
        sudo apt-get install -y libopenblas-dev libatlas-base-dev liblapack-dev gfortran libgmp-dev libmpfr-dev libsuitesparse-dev ccache libmpc-dev libjpeg-dev zlib1g-dev libtiff-dev libfreetype6-dev liblcms2-dev libwebp-dev
 
    - name: Install dependencies
      run: |
        python -c "import platform; print(platform.platform()); print(platform.architecture())"
        if [[ "${{ matrix.python-version }}" == "3.13t" ]]; then
          # Use pip for 3.13t (free-threading) as uv may not fully support it yet
          python -m pip install --upgrade pip
          pip install -e .[test]
        else
          uv pip install --system -e .[test]
        fi
      shell: bash
    - name: Add numba
      if: ${{ !contains(fromJSON('["pypy3.11", "3.13t"]'), matrix.python-version) }}
      run: |
        uv pip install --system -e .[numba]
    - name: Test with pytest
      run: |
        pytest . -v --cov-report html --cov=ht --cov-report term-missing -m "not online and not thermo"
        coveralls || true
      env:
        COVERALLS_REPO_TOKEN: ${{ secrets.coveralls }}
        COVERALLS_PARALLEL: true
        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        PYTHON_GIL: ${{ matrix.python-version == '3.13t' && '0' || '' }}
 
    - name: Upload coverage HTML report
      if: always()
      uses: actions/upload-artifact@v4
      with:
        name: coverage-html-${{ matrix.os }}-${{ matrix.python-version }}-${{ matrix.architecture }}
        path: htmlcov/
  finish:
    timeout-minutes: 30
    needs: build
    runs-on: latchkey-small
    steps:
    - name: Coveralls Finished
      env:
        COVERALLS_REPO_TOKEN: ${{ secrets.coveralls }}
        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
      run: |
        curl https://coveralls.io/webhook?repo_token=${{ secrets.coveralls }} -d "payload[build_num]=${{ github.sha }}&payload[status]=done"

What changed

Run on Latchkey managed runners with one line (runs-on), which apply the fixes below automatically and self-heal transient failures. This example uses latchkey-small; pick the runner size that fits the job.
Cache dependency installs on the setup step so they are served from cache.
Add a job timeout so a hung step cannot burn hours of runner time.

1 third-party action is referenced by a movable tag. Pin it to the commit SHA (Latchkey resolves and applies this automatically) so a repointed tag cannot change what runs.

What Latchkey heals here

This workflow has steps that commonly fail on transient issues (network, registries, flaky browsers). On Latchkey managed runners they are detected, retried, and self-healed instead of failing your build:

Dependency installs
Network fetches

This workflow runs 2 jobs (57 with the matrix expanded) per trigger. On Latchkey the same minutes cost up to 58% less than GitHub-hosted, with zero queue time.

Actions used in this workflow

actions/checkout actions/setup-python astral-sh/setup-uv actions/upload-artifact