Checks workflow (scrapy/scrapy)

The Checks workflow from scrapy/scrapy, explained and optimized by Latchkey.

What it does

This is the Checks workflow from the scrapy/scrapy repository, a real project running GitHub Actions. It is shown here with attribution under its BSD-3-Clause license.

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

The workflow

name: Checks
on:
  push:
    branches:
    - master
    - '[0-9]+.[0-9]+'
  pull_request:

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

jobs:
  checks:
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        include:
        - python-version: "3.14"
          env:
            TOXENV: pylint
        - python-version: "3.10"
          env:
            TOXENV: mypy
        - python-version: "3.10"
          env:
            TOXENV: mypy-tests
        # Keep in sync with pyproject.toml tool.sphinx-scrapy.python-version.
        - python-version: "3.14"
          env:
            TOXENV: docs
        - python-version: "3.13"
          env:
            TOXENV: docs-tests
        - python-version: "3.14"
          env:
            TOXENV: twinecheck

    steps:
    - uses: actions/checkout@v6

    - name: Set up Python ${{ matrix.python-version }}
      uses: actions/setup-python@v6
      with:
        python-version: ${{ matrix.python-version }}

    - name: Run check
      env: ${{ matrix.env }}
      run: |
        pip install -U tox
        tox

  pre-commit:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v6
    - uses: pre-commit/action@v3.0.1

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: Checks
on:
  push:
    branches:
    - master
    - '[0-9]+.[0-9]+'
  pull_request:
 
concurrency:
  group: ${{github.workflow}}-${{ github.ref }}
  cancel-in-progress: true
 
jobs:
  checks:
    timeout-minutes: 30
    runs-on: latchkey-small
    strategy:
      fail-fast: false
      matrix:
        include:
        - python-version: "3.14"
          env:
            TOXENV: pylint
        - python-version: "3.10"
          env:
            TOXENV: mypy
        - python-version: "3.10"
          env:
            TOXENV: mypy-tests
        # Keep in sync with pyproject.toml tool.sphinx-scrapy.python-version.
        - python-version: "3.14"
          env:
            TOXENV: docs
        - python-version: "3.13"
          env:
            TOXENV: docs-tests
        - python-version: "3.14"
          env:
            TOXENV: twinecheck
 
    steps:
    - uses: actions/checkout@v6
 
    - name: Set up Python ${{ matrix.python-version }}
      uses: actions/setup-python@v6
      with:
        cache: 'pip'
        python-version: ${{ matrix.python-version }}
 
    - name: Run check
      env: ${{ matrix.env }}
      run: |
        pip install -U tox
        tox
 
  pre-commit:
    timeout-minutes: 30
    runs-on: latchkey-small
    steps:
    - uses: actions/checkout@v6
    - uses: pre-commit/action@v3.0.1
 

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

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

Actions used in this workflow