The CS builds also have a futures timeout, seen in a few places: https://github.com/racket/racket/runs/3362632934?check_suite_focus=true https://github.com/racket/racket/runs/3376527479?check_suite_focus=true https://github.com/racket/racket/runs/3378213861?check_suite_focus=true which seems to be in the shutdown-stress.rkt test.