Function workspace_digest 

pub fn workspace_digest(root: &Path) -> String

Identity of one owner tree: sha256 of its canonical spelling, the first 16 lowercase hex characters.

The spelling is absolute_path, so macOS’s /var and /private/var, a/../b and b, and C:\Work and c:/work each digest alike — the whole reason a daemon and every client can derive one file name without talking to each other. Both runtime files of a tree share this digest, one leaf apart.