Check PR Source Branch workflow (huggingface/nanotron)

The Check PR Source Branch workflow from huggingface/nanotron, explained and optimized by Latchkey.

What it does

This is the Check PR Source Branch workflow from the huggingface/nanotron 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: Check PR Source Branch
on:
  pull_request:
    branches:
      - main

jobs:
  check-branch:
    runs-on: ubuntu-latest
    steps:
      - name: Check PR source branch
        if: github.base_ref == 'main' && github.head_ref != 'dev'
        run: |
          echo "ERROR: PRs to main must come from dev branch"
          exit 1

The same workflow, on Latchkey

Removes redundant runs and caps runaway jobs. Added and changed lines are highlighted.

name: Check PR Source Branch
on:
  pull_request:
    branches:
      - main
 
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true
 
jobs:
  check-branch:
    timeout-minutes: 30
    runs-on: latchkey-small
    steps:
      - name: Check PR source branch
        if: github.base_ref == 'main' && github.head_ref != 'dev'
        run: |
          echo "ERROR: PRs to main must come from dev branch"
          exit 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.
• Cancel superseded runs when a branch or PR gets a newer push.
• Add a job timeout so a hung step cannot burn hours of runner time.

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