def build_single_worker(queue, templates, base_output_dir):
    """Worker thread for picking up scheme files from $queue and building b16
    templates using $templates until it receives None."""
    while True:
        scheme_file = queue.get()
        if scheme_file is None:
            break
        build_single(scheme_file, templates, base_output_dir)
        queue.task_done()
Worker thread for picking up scheme files from $queue and building b16
    templates using $templates until it receives None.