code: private List<WyilFile> getExternals() throws IOException {
  		ArrayList<WyilFile> externals = new ArrayList<>();
  		List<Build.Package> pkgs = project.getPackages();
  		// Consider each package in turn and identify all contained WyilFiles
  		for (int i = 0; i != pkgs.size(); ++i) {
  			Build.Package p = pkgs.get(i);
  			// FIXME: This is kind broken me thinks. Potentially, we should be able to
  			// figure out what modules are supplied via the configuration.
  			List<Path.Entry<WyilFile>> entries = p.getRoot().get(Content.filter("**/*", WyilFile.ContentType));
  			for (int j = 0; j != entries.size(); ++j) {
  				externals.add(entries.get(j).read());
  			}
  		}
  		return externals;
  	}
docs: Read in all external packages so they can be used for name resolution. This
  amounts to loading in every WyilFile contained within an external package
  dependency.