A backup uploads its blobs before the manifest that lists them, and the
process lock covers one user on one machine, so a prune from another host
or user sharing the destination deleted a running backup's blobs.
Prune now deletes an unreferenced blob only once its listed time is older
than the new config key prune_grace_period (default 24h; a negative value
is refused). A newer blob, or one listed with no time, is kept and counted
(blobs_too_new). The rclone backend takes each object's time from the
listing (use_server_modtime).
Decision: a blob a backup reuses from an earlier run that stopped before
its manifest keeps its old time and is not protected; the docs and config
comments say so.
Model: opus-5-5
sneak