Function commons_dir_for 

pub fn commons_dir_for(name: &str) -> PathBuf

The path a unit’s name maps to, relative to a source or output root: a.b is a/b. A dependency’s canonical unit name (#2223, crate::packages::PackageId::encoded) maps under deps/<org>/<package>/, so every name-to-path site lays a dependency’s units out there without knowing about packages.