Function read_bynk_tree_single 

pub fn read_bynk_tree_single(
    root: &Path,
) -> Result<HashMap<PathBuf, String>, DiscoveryError>

read_bynk_tree with no excludes — the common case for a single-root project (CompileOptions::single, whose own Roots::excludes() is always empty) and for test fixtures, which rarely declare an exclude list.