Function build_sibling_binary 

pub fn build_sibling_binary(
    repo: &Path,
    sibling: &str,
    bin: &str,
    dependency_checkouts: &[&str],
) -> PathBuf

Build a sibling using a cache key derived from its current source revision and caller-selected adjacent dependency checkouts. The same dependency names are checked again after compilation to reject sources changed during the build.