The size of requests.queue may be wrong when resuming crawl from unclean shutdown. #3333
Scrapy 隐含 bug: 强制关闭爬虫后从 requests.queue 读取的已保存 request 数量可能有误
原文：https://www.cnblogs.com/my8100/p/scrapy_hidden_bug_of_requests_queue.html
