Function resolve_dep_roots 

pub fn resolve_dep_roots(
    project_root: &Path,
    manifest: &Manifest,
) -> Result<Vec<DepRoot>, CliError>

Resolve the manifest’s linkable dependencies against project_root into the loader’s DepRoots. A resolution failure (a floating git rev, a missing path, an unlinkable form) surfaces as a clean CliError, so every command that links deps reports the same message.