pub fn runtime_dir_placement(
workdir: &Path,
) -> Result<RuntimeDirPlacement, HomeUnusable>Expand description
Where the runtime directory and the records directory would lie relative to workdir, the
session’s workdir root. Creates nothing.
Each path is resolved by canonicalizing its nearest existing ancestor and appending the rest,
so a workdir that does not exist yet, or a home with no .murmur in it yet, is judged by
where it would be created.