Build workflow (psf/pyperf)

The Build workflow from psf/pyperf, explained and optimized by Latchkey.

CI health: D - needs work

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

Grade your own workflow free or run it on Latchkey →

Source: psf/pyperf.github/workflows/build.ymlLicense MITView source

What it does

This is the Build workflow from the psf/pyperf 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, pull_request, workflow_dispatch]

permissions: {}

env:
  FORCE_COLOR: 1

jobs:
  tox-jobs:
    strategy:
      fail-fast: false
      matrix:
        tox-job: [doc, pep8]
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
        with:
          python-version: 3.x
      - run: pip install tox
      - run: tox -e ${{ matrix.tox-job }}
  build:
    runs-on: ${{ matrix.os }}
    name: ${{ matrix.os }} - ${{ matrix.python }} ${{ matrix.build }}
    strategy:
      matrix:
        os: [ubuntu-latest, macos-latest, windows-latest, ubuntu-24.04-arm]
        python: ['3.12']
        build: ['']
        include:
          - os: ubuntu-latest
            python: 'pypy3.10'
          - os: ubuntu-latest
            python: 'pypy3.9'
          - os: ubuntu-latest
            python: '3.9'
          - os: ubuntu-latest
            python: '3.10'
          - os: ubuntu-latest
            python: '3.11'
          - os: ubuntu-latest
            python: '3.12'
          - os: ubuntu-latest
            python: '3.13-dev'
            build: 'free-threading'

    steps:
      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Setup Python
        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
        if: ${{ matrix.build != 'free-threading' }}
        with:
          python-version: ${{ matrix.python }}
      - name: Set up Python ${{ matrix.python }} using deadsnakes
        uses: deadsnakes/action@e640ac8743173a67cca4d7d77cd837e514bf98e8 # v3.2.0
        if: ${{ matrix.build == 'free-threading' }}
        with:
          python-version: ${{ matrix.python }}
          nogil: true
      - name: Display Python version
        run: |
          python -VV
          python -c 'import sysconfig; print("Free threading?", "Yes" if sysconfig.get_config_var("Py_GIL_DISABLED") else "No")'
      - name: Install Tox and any other packages
        run: pip install tox
      - name: Run Tox
        # Run tox using the version of Python in `PATH`
        run: tox -e py

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, pull_request, workflow_dispatch]
 
permissions: {}
 
env:
  FORCE_COLOR: 1
 
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true
 
jobs:
  tox-jobs:
    timeout-minutes: 30
    strategy:
      fail-fast: false
      matrix:
        tox-job: [doc, pep8]
    runs-on: latchkey-small
    steps:
      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
        with:
          cache: 'pip'
          python-version: 3.x
      - run: pip install tox
      - run: tox -e ${{ matrix.tox-job }}
  build:
    timeout-minutes: 30
    runs-on: ${{ matrix.os }}
    name: ${{ matrix.os }} - ${{ matrix.python }} ${{ matrix.build }}
    strategy:
      matrix:
        os: [ubuntu-latest, macos-latest, windows-latest, ubuntu-24.04-arm]
        python: ['3.12']
        build: ['']
        include:
          - os: ubuntu-latest
            python: 'pypy3.10'
          - os: ubuntu-latest
            python: 'pypy3.9'
          - os: ubuntu-latest
            python: '3.9'
          - os: ubuntu-latest
            python: '3.10'
          - os: ubuntu-latest
            python: '3.11'
          - os: ubuntu-latest
            python: '3.12'
          - os: ubuntu-latest
            python: '3.13-dev'
            build: 'free-threading'
 
    steps:
      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: Setup Python
        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
        if: ${{ matrix.build != 'free-threading' }}
        with:
          cache: 'pip'
          python-version: ${{ matrix.python }}
      - name: Set up Python ${{ matrix.python }} using deadsnakes
        uses: deadsnakes/action@e640ac8743173a67cca4d7d77cd837e514bf98e8 # v3.2.0
        if: ${{ matrix.build == 'free-threading' }}
        with:
          python-version: ${{ matrix.python }}
          nogil: true
      - name: Display Python version
        run: |
          python -VV
          python -c 'import sysconfig; print("Free threading?", "Yes" if sysconfig.get_config_var("Py_GIL_DISABLED") else "No")'
      - name: Install Tox and any other packages
        run: pip install tox
      - name: Run Tox
        # Run tox using the version of Python in `PATH`
        run: tox -e py

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.
Cancel superseded runs when a branch or PR gets a newer push.
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.

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

This workflow runs 2 jobs (6 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