commit-cloud

Draft Sapling stacks backed up from one machine appear on the others after their next scripts/pull, with hashes, dates and branches intact, beside that machine's own stacks and not checked out. Backing up is explicit; restoring happens on pull. Inspired by Meta's commit cloud, which open-source Sapling disables for git repos.

Commands

• Back up: scripts/commit-cloud backup [<checkout>...]. Backs up every Sapling checkout under projects/, or those named, and restores what others backed up. Run it when asked to back up a stack, and before a machine is left. There is no per-stack mode: a checkout's draft heads are backed up as a set, which is what lets the set converge.
• Restore only: scripts/commit-cloud restore <checkout>, which scripts/pull runs for a Sapling checkout before returning to the branch or commit it started on. It also prints a pending line when the checkout's own stacks are not backed up, with the command to run.
• Opt in: the first explicit backup clones the repo to .commit-cloud/. Before that, restore and the pull hook do nothing. The repo must exist on GitHub, private and never a fork; git config devroot.commitCloud at the root names another as owner/repo or a URL.

Reading the output

Each line is an action on one head, by its 12-character hash: back up, retract, revive, restore … from <host>/<slot> as <branches>, bookmark … as <host>/backup-<date>, hide, keep, pending. Exit 3 means something needs a human, and the message says what: the repo is unreachable, the push was rejected, or a stack's base is on no remote here.

Resuming a restored stack

• It shows in sl smartlog as ordinary drafts, with the producer's task branch recreated and a bookmark <host>/backup-<yyyymmdd>, dated by the stack's tip commit, with -1, -2 for more from the same host and day.
• Resume with git switch <branch> to commit on the task branch, or sl goto <bookmark> or sl goto <hash>. Nothing else changes the working copy.
• A restored stack is never backed up again by the machine that restored it. Work committed on top of it is new work, and the next backup carries it.

How the set converges