code: def main():
      
      try:
          pkg_version = Update()
          if pkg_version.updatable():
              pkg_version.show_message()
          metadata = control.retreive_metadata()
          parser = parse_options(metadata)
          argvs = sys.argv
          if len(argvs) <= 1:
              parser.print_help()
              sys.exit(1)
          args = parser.parse_args()
          control.print_licences(args, metadata)
          control.check_repository_existence(args)
          control.check_package_existence(args)
          control.generate_package(args)
      except (RuntimeError, BackendFailure, Conflict) as exc:
          sys.stderr.write('{0}\n'.format(exc))
          sys.exit(1)
docs: Execute main processes.