Commit Management

Because CI takes so long, we use a token-passing scheme to coordinate landing commits on trunk. We want to avoid changing trunk at a surprising time, invalidating the next person's CI run,

Previously, we used the keybase #engineering channel to coordinate this. The practice was to change the "headline" (topic) of the channel to Q:[name1, name2] to establish a queue of people allowed to land. Sometime we used Q:[name1#PRnum, ..] to make it more explicit (also giving name2 implicit permission to claim the token if the given PR had already landed, usually done in conjunction with GitHub's auto-merge setting).

We're experimenting with https://mergify.io now, @mfig is driving.