Every backup writes vaultik-destination.txt at the destination root.
While the local index holds snapshots, a destination without it is
not present: snapshot create refuses before writing, prune and
snapshot purge fail, snapshot list and snapshot remove warn. remote
nuke deletes it last. The file:// backend no longer creates its
destination directory and checks for it on every write, which
protects a directory on a removable volume but not a mount point.
Tests back up into directories that exist; fixtures standing for a
written destination carry the marker, and two tests check they get
past it.
Judgement call: the marker is rewritten on every backup.
Deviation: for the complexity limit, snapshot name selection moved
into snapshotNamesToCreate and the --force/--json test into
confirmRemoveSnapshot, both unchanged.
Model: opus-5-5
snapshot purge, and the purge step of snapshot create --prune, logged a
failure to delete a snapshot from the local index, deleted that
snapshot's metadata from the destination store anyway, and exited 0. The
purge now stops at that snapshot with an error before touching its
remote metadata, so the command exits non-zero. Stopping matches what
the same loop already does when the remote delete fails; snapshots
purged before the failure stay purged.
The test drives snapshot purge only: the trigger that makes the local
index refuse the delete also breaks the backup's metadata export, so
snapshot create --prune cannot be tested that way.
Model: opus-5-5