Function read_package_config 

pub fn read_package_config(
    project_root: &Path,
    overlay: &HashMap<PathBuf, String>,
) -> Option<PackageConfig>

The project’s [package] as both the build and the editor see it, the way crate::read_unstable_config reads [unstable]: the overlay’s bynk.toml when it holds one, otherwise the one on disk. None when there is no manifest, no [package], or one that isn’t well formed: its shape errors are crate::check_manifest’s to report.