It is sometimes desirable for a job (such as a branch project) to simply abort any previously running builds as soon as a new build starts. For example, in a branch project for a pull request, you might want to see test results from an earlier commit even after pushing follow-up commits, but most of the time you only care about the results of the PR head, and computer time might be too valuable to waste on the older ones.
(I think gerrit-trigger does something like this automatically, and I have seen grayaii invent the same kind of pattern with JenkinsPy.)
Merely setting the job to not be concurrent-capable does not suffice, since then newer builds will queue up waiting for the older ones to finish.
Manual equivalent courtesy of bsquizz: