Simply looking at the Resolve struct definition tells you. /// A map from packages to a set of their public dependencies public_dependencies: HashMap<P

Simply looking at the Resolve struct definition tells you. /// A map from packages to a set of their public dependencies public_dependencies: HashMap<PackageId, HashSet<PackageId>>, I do agree with you that Rust is easier to read in an IDE though, since then those types gets autoresolved and hinted inline for you.