Evaluate diff workflow (Lightning-AI/torchmetrics)

The Evaluate diff workflow from Lightning-AI/torchmetrics, explained and optimized by Latchkey.

What it does

This is the Evaluate diff workflow from the Lightning-AI/torchmetrics repository, a real project running GitHub Actions. It is shown here with attribution under its Apache-2.0 license.

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

The workflow

name: Evaluate diff

on:
  workflow_call:
    # Map the workflow outputs to job outputs
    outputs:
      test-dirs:
        description: "Test folders"
        value: ${{ jobs.eval-diff.outputs.focus }}

jobs:
  eval-diff:
    runs-on: ubuntu-latest
    timeout-minutes: 5
    # Map the job outputs to step outputs
    outputs:
      focus: ${{ steps.diff-domains.outputs.focus }}
    steps:
      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
      - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0

      - name: Get PR diff
        id: diff-domains
        env:
          PR_NUMBER: "${{ github.event.pull_request.number }}"
        run: |
          set -e
          echo $PR_NUMBER
          pip install -q -U packaging fire pyGithub pyopenssl
          echo "focus=$(python .github/assistant.py changed-domains $PR_NUMBER)" >> $GITHUB_OUTPUT

      - run: echo "${{ steps.diff-domains.outputs.focus }}"

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: Evaluate diff
 
on:
  workflow_call:
    # Map the workflow outputs to job outputs
    outputs:
      test-dirs:
        description: "Test folders"
        value: ${{ jobs.eval-diff.outputs.focus }}
 
jobs:
  eval-diff:
    runs-on: latchkey-small
    timeout-minutes: 5
    # Map the job outputs to step outputs
    outputs:
      focus: ${{ steps.diff-domains.outputs.focus }}
    steps:
      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
      - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
        with:
          cache: 'pip'
 
      - name: Get PR diff
        id: diff-domains
        env:
          PR_NUMBER: "${{ github.event.pull_request.number }}"
        run: |
          set -e
          echo $PR_NUMBER
          pip install -q -U packaging fire pyGithub pyopenssl
          echo "focus=$(python .github/assistant.py changed-domains $PR_NUMBER)" >> $GITHUB_OUTPUT
 
      - run: echo "${{ steps.diff-domains.outputs.focus }}"
 

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.

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 1 job per trigger. On Latchkey the same minutes cost up to 58% less than GitHub-hosted, with zero queue time.

Actions used in this workflow