This is primarily useful to automatically cancel jobs while updating PRs repeatedly in short succession, especially since macOS and Windows builds take quite a bit of time (and the number of parallel jobs is limited).
One note: this could cancel a main job if two PRs were merged right after each other, but that's fine: the checks with the final merge would eventually get run.
A small GitHub Actions change, as specified here: https://docs.github.com/en/actions/learn-github-actions/workflow-syntax-for-github-actions#concurrency
This is primarily useful to automatically cancel jobs while updating PRs repeatedly in short succession, especially since macOS and Windows builds take quite a bit of time (and the number of parallel jobs is limited).
One note: this could cancel a
main
job if two PRs were merged right after each other, but that's fine: the checks with the final merge would eventually get run.