Bug 1403222 added the following lines to testing/marionette/moz.build: > with Files("harness/**"): > SCHEDULES.exclusive = ["marionette", "firefox-ui"] If I understand this correctly, any changes under this folder should only trigger the marionette and firefox-ui tests. What we actually have in this case is the following: Under `testing/marionette/harness/marionette_harness/tests` there are only tests, which would have to trigger the `marionette` job. Only real harness changes have to trigger other harnesses which are based on marionette which are: * firefox-ui tests * telemetry tests