Nightly cron update runs considerably after the new nightly has been released

[RalfJung]

It looks like the nightly update on the playground runs around 8am UTC, i.e., quite considerably after the new nightly has been released. It just happened the second time that I went to the playground in the morning to play with a feature that landed the day before and was surprised why it was not available yet. ;)

Unfortunately, Travis cron job configuration is quite awful and does not let you pick the time the job runs. So to move it earlier, you have to be awake at that time and then delete and re-configure the cron job in the travis settings. However, if you are in the US timezone, that means it shouldn't be too hard to get one configured for around 3am UTC (9am at the East Coast) or so, when the new nightly should definitely be up. Being in a European timezone, my own cron jobs usually run around 7am UTC as I rarely get up earlier than that...^^

[RalfJung]

It also seems like Travis moves these jobs around sometimes; some of my jobs that used to be nice and early in the morning to test new nightlies fresh as they come out are now in the afternoon. :/

[shepmaster]

A middle ground solution would be to switch from Travis to something more maintained. GitHub Actions allows more granular cron scheduling, for example. Then we just run it every hour (nothing should rebuild when unchanged)

A more “correct” solution would be to somehow watch the rustup artifacts and trigger builds when there are new ones. Not sure how best to configure that.