We have several plugins added, which show useful information to the right of build instances. One plugin shows the size of that build's artifacts; another shows how it was started (from upstream, or by human, etc). Another is the job config history, which shows a wrench if this job's configuration changed prior to running that instance.

It is possible that the job's configuration has changed since the most recent instance, and this is not currently shown.

Would it be possible to show this in the UI?

My initial thought was to have it add a "build instance" at the top: with a gray ball to indicate "not run", the next #, and text like "not run yet" in the place where the date/timestamp would be, and a wrench to the right of it to indicate that the configuration has already changed.

However, I'm not sure whether that would perturb other plugins (e.g., they might see the existence of "another" build and try to take some action, which may fail because it's not really there). If that would be the case, then if a control could be added above the builds and below the left menu, a notification could be added there.