From https://chromium-review.googlesource.com/c/chromium/tools/build/+/744043:

> > > Out of curiosity, why does the publish_tarball builder trigger itself when there is work to do, rather than just starting to do that work immediately?
> > 
> > Sorry, I don't follow.
> > 
> > AFAICS in masters/master.chromium.infra.cron/master.cfg, publish_tarball is triggered periodically and, from, https://ci.chromium.org/buildbot/chromium.infra.cron/publish_tarball/8791, it gets to work immediately without an intermediate trigger step.
> 
> The build is started every 3 hours, yes. But the build that was started on the three hour mark was
> https://ci.chromium.org/buildbot/chromium.infra.cron/publish_tarball/8790
> which then ran a trigger step, causing
> https://ci.chromium.org/buildbot/chromium.infra.cron/publish_tarball/8791
> to start one minute later. This seems totally unnecessary.