fn generate_roots(
ret: &mut HashMap<CompileKind, Vec<Unit>>,
default: &'static str,
crates: &[String],
units: &[Unit],
std_resolve: &Resolve,
std_features: &ResolvedFeatures,
kinds: &[&CompileKind],
package_set: &PackageSet<'_>,
interner: &UnitInterner,
profiles: &Profiles,
target_data: &RustcTargetData<'_>,
) -> CargoResult<()>