CI workflow (PyCQA/isort)

The CI workflow from PyCQA/isort, explained and optimized by Latchkey.

CI health: F - at risk

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Source: PyCQA/isort.github/workflows/continuous-integration.ymlLicense MITView source

What it does

This is the CI workflow from the PyCQA/isort 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: CI

"on":
  push:
    branches:
      - main
  pull_request:
  merge_group:

permissions:
  contents: read

env:
  DEFAULT_PYTHON: "3.14"

jobs:
  lint:
    name: Lint
    runs-on: ubuntu-latest

    steps:
      - &checkout
        name: Check out the repository
        uses: actions/checkout@v7
        with:
          fetch-depth: 2

      - &setup-python
        name: Set up Python ${{ env.DEFAULT_PYTHON }}
        uses: actions/setup-python@v6.0.0
        with:
          python-version: ${{ env.DEFAULT_PYTHON }}
          check-latest: true

      - &setup-uv
        name: Install UV
        uses: astral-sh/setup-uv@v7
        with:
          enable-cache: true
          version-file: "pyproject.toml"

      - &install-dependencies
        name: Install dependencies
        run: uv sync --all-extras --frozen

      - name: Lint
        run: uv run --with tox-uv tox -e lint

  build:
    if: github.repository_owner == 'PyCQA'
    name: Build
    runs-on: ubuntu-latest
    
    steps:
      - *checkout
      - *setup-python
      - *setup-uv

      - name: Build package
        run: uv build

  test:
    name: Tests
    strategy:
      fail-fast: false
      matrix:
        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14", "3.15"]
        os: [ubuntu-latest, macos-latest, windows-latest]
    runs-on: ${{ matrix.os }}
    env:
      FORCE_COLOR: 1

    steps:
      - *checkout
     
      - name: Set up Python ${{ matrix.python-version }}
        uses: actions/setup-python@v6
        with:
          python-version: ${{ matrix.python-version }}
          allow-prereleases: true
          check-latest: true

      - *setup-uv
      - *install-dependencies

      - name: Run tests
        run: uv run --with tox-uv tox -e py,coverage_report-ci

      - name: Report Coverage
        if: matrix.os == 'ubuntu-latest' && matrix.python-version == ${{ env.DEFAULT_PYTHON }}
        uses: codecov/codecov-action@v7


  integration:
    name: Integration tests
    runs-on: ubuntu-latest

    steps:
      - *checkout
      - *setup-python
      - *setup-uv
      - *install-dependencies

      - name: Test integration
        run: ./scripts/test_integration.sh

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: CI
 
"on":
  push:
    branches:
      - main
  pull_request:
  merge_group:
 
permissions:
  contents: read
 
env:
  DEFAULT_PYTHON: "3.14"
 
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true
 
jobs:
  lint:
    timeout-minutes: 30
    name: Lint
    runs-on: latchkey-small
 
    steps:
      - &checkout
        name: Check out the repository
        uses: actions/checkout@v7
        with:
          fetch-depth: 2
 
      - &setup-python
        name: Set up Python ${{ env.DEFAULT_PYTHON }}
        uses: actions/setup-python@v6.0.0
        with:
          cache: 'pip'
          python-version: ${{ env.DEFAULT_PYTHON }}
          check-latest: true
 
      - &setup-uv
        name: Install UV
        uses: astral-sh/setup-uv@v7
        with:
          enable-cache: true
          version-file: "pyproject.toml"
 
      - &install-dependencies
        name: Install dependencies
        run: uv sync --all-extras --frozen
 
      - name: Lint
        run: uv run --with tox-uv tox -e lint
 
  build:
    timeout-minutes: 30
    if: github.repository_owner == 'PyCQA'
    name: Build
    runs-on: latchkey-small
    
    steps:
      - *checkout
      - *setup-python
      - *setup-uv
 
      - name: Build package
        run: uv build
 
  test:
    timeout-minutes: 30
    name: Tests
    strategy:
      fail-fast: false
      matrix:
        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14", "3.15"]
        os: [ubuntu-latest, macos-latest, windows-latest]
    runs-on: ${{ matrix.os }}
    env:
      FORCE_COLOR: 1
 
    steps:
      - *checkout
     
      - name: Set up Python ${{ matrix.python-version }}
        uses: actions/setup-python@v6
        with:
          cache: 'pip'
          python-version: ${{ matrix.python-version }}
          allow-prereleases: true
          check-latest: true
 
      - *setup-uv
      - *install-dependencies
 
      - name: Run tests
        run: uv run --with tox-uv tox -e py,coverage_report-ci
 
      - name: Report Coverage
        if: matrix.os == 'ubuntu-latest' && matrix.python-version == ${{ env.DEFAULT_PYTHON }}
        uses: codecov/codecov-action@v7
 
 
  integration:
    timeout-minutes: 30
    name: Integration tests
    runs-on: latchkey-small
 
    steps:
      - *checkout
      - *setup-python
      - *setup-uv
      - *install-dependencies
 
      - name: Test integration
        run: ./scripts/test_integration.sh

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.

2 third-party actions are referenced by a movable tag. Pin them to the commit SHA (Latchkey resolves and applies this automatically) so a repointed tag cannot change what runs.

This workflow runs 4 jobs (21 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 codecov/codecov-action