pub fn prune_dir(dir: &Path, limit: u64) -> Result<Prune>Expand description
Delete files under dir oldest-first until its size is at or below limit.
The comparison is over_limit, so a directory exactly at the cap is left
alone. Oldest-first keeps the newest generation of artifacts — the one the
next run reuses — and sheds the generations that only compile history. A
deleted file costs the next build a rebuild of that one unit; deleting the
whole directory would cost it everything, which is precisely the work
prune_dir is keeping for it.
Empty directories left behind are swept depth-first, so cargo’s deep
fingerprint/deps trees do not outlive the files that made them.
Nothing is deleted when the directory is missing.