Scrapy get website with error "DNS lookup failed"

I'm trying to use Scrapy to get all links on websites where the "DNS lookup failed".

The problem is, every website without any errors are print on the parse_obj method but when an url return DNS lookup failed, the callback parse_obj is not call.

I want to get all domain with the error "DNS lookup failed", how can I do that ?

Logs :

2016-03-08 12:55:12 [scrapy] INFO: Spider opened
2016-03-08 12:55:12 [scrapy] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)
2016-03-08 12:55:12 [scrapy] DEBUG: Telnet console listening on 127.0.0.1:6023
2016-03-08 12:55:12 [scrapy] DEBUG: Crawled (200) <GET http://domain.com> (referer: None)
2016-03-08 12:55:12 [scrapy] DEBUG: Retrying <GET http://expired-domain.com/> (failed 1 times): DNS lookup failed: address 'expired-domain.com' not found: [Errno 11001] getaddrinfo failed.

Code :

class MyItem(Item):
    url= Field()

class someSpider(CrawlSpider):
    name = 'Crawler'        
    start_urls = ['http://domain.com']
    rules = (Rule(LxmlLinkExtractor(allow=()), callback='parse_obj', follow=True),)

    def parse_obj(self, response):
        item = MyItem()
        item['url'] = []
        for link in LxmlLinkExtractor(allow=()).extract_links(response):
            parsed_uri = urlparse(link.url)
            url = '{uri.scheme}://{uri.netloc}/'.format(uri=parsed_uri)
            print url