Constant VOLUME_PICK_STAMP_PREFIX 

pub const VOLUME_PICK_STAMP_PREFIX: &str = "volume-pick-";

Prefix of the per-engine stamp a completed volume dry run leaves in the config directory (volume-pick-docker.stamp holds the Unix time it finished). The real --include-volumes pick list only arms while a stamp is fresh, so the first time anyone types the real command they get the dry run instead of a deletion prompt.