def has_archiver_index(config, archiver):
root = pathlib.Path(config.cache_path) / archiver / "<STR_LIT>"<EOL>return root.exists()<EOL>
Check if this archiver has an index file.

:param config: The configuration
:type  config: :class:`wily.config.WilyConfig`

:param archiver: The name of the archiver type (e.g. 'git')
:type  archiver: ``str``

:return: the exist
:rtype: ``bool``