当我尝试抓取以下网址时，出现DNS查找错误。网址：http://extremecouponprofessors.net/2012/03/anyone-get-cash-in-the-mail-today-im-not-kidding-i-got-cash-lol/
错误：
DNS lookup failed: address 'http://extremecouponprofessors.net/2012/03/anyone-get-cash-in-the-mail-today-im-not-kidding-i-got-cash-lol/' not found: timeout error.
访问w / scrapy shell时出现同样的错误
scrapy shell "http://extremecouponprofessors.net/2012/03/anyone-get-cash-in-the-mail-today-im-not-kidding-i-got-cash-lol/"
Scrapy Shell错误：
elif failure.check(DNSLookupError): SyntaxError: invalid syntax
dig extremecouponprofessors.net：
; <<>> DiG 9.8.3-P1 <<>> extremecouponprofessors.net
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 9017
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;extremecouponprofessors.net. IN A
;; ANSWER SECTION:
extremecouponprofessors.net. 4563 IN A 198.136.50.148
;; Query time: 7 msec
;; SERVER: 192.168.101.7#53(192.168.101.7)
;; WHEN: Wed Nov 18 16:12:00 2015
;; MSG SIZE rcvd: 61