[kiallmacinnes]

The issue is with how GitHub (and most PR / CI systems...) relies on stale CI results.

Master/Main changed between the tests running for that PR, and it merging. Why should those test results be considered a useful indicator for what happens after the PR merges anymore?

GitHub does have a setting you can enable to help with this, essentially, when any PR merges, it forces the developer to rebase any open PRs. A huge waste of effort, so nobody turns it in.

There are far better systems out there, e.g. zuul-ci.org which was designed to handle this exact problem at scale. Others have mentioned GitLab merge trains, though I've never used them - so hard to tell if they really solve this :)