def no_cache_dir_callback(option, opt, value, parser):
<EOL>if value is not None:<EOL><INDENT>try:<EOL><INDENT>strtobool(value)<EOL><DEDENT>except ValueError as exc:<EOL><INDENT>raise_option_error(parser, option=option, msg=str(exc))<EOL><DEDENT><DEDENT>parser.values.cache_dir = False<EOL>
Process a value provided for the --no-cache-dir option.

This is an optparse.Option callback for the --no-cache-dir option.