CI failure messages over #buildkite-main are not actionnable enough

Created by: jhchabran

Right now, when a build fails, the standard message failure message is posted in #buildkite-main, mentioning its author.

The only thing it achieves is notifying the author that something went wrong. So the channel is a long list of failures, with some of them being threads where teammates are debating how to fix the problem or address the flake.

The flow is usually that someone will take a look at the failure, check what caused it, and will eventually post it in the chan if there is reason to think it could be fixed shortly.

Therefore, unless you're actively monitoring or getting pinged, you'll never see that your flaking tests are affecting others, which when a test suite stays flaky for too long, usually end up being ignored.

By adding more information to the failure messages, we can put the source of failures in front of us, which will create more engagement to fix problems, because you can't ignore that your test suite is interrupting your colleague.

This is not the ultimate solution to creating more engagement around failures, but one of the measures we can take to spark more initiative and reactiveness from everyone.