struct.error: unpack requires a string argument of length 4

摘要: 报错如下，总而言之就是三个字：看不懂！！！线下一直运行正常，一到线上就运行错误，最后发现线上少一个openssl库，安装后正常了。。。。。。也不知道为啥

就在刚刚，发现了根本问题，因为爬虫用的jobdir，公司原来用的python2，我后来用的python3，两个程序同时指向了一个jobdir，python2和3编码格式不一样所以导致了问题

Exception:
suara_travel ERROR:
2018-01-31 20:03:16 [twisted] CRITICAL: Unhandled Error
Traceback (most recent call last):
File "/root/airflow_crawl/beritaqu-crawl/wkd/commands/crawl.py", line 65, in run
self.crawler_process.start()
File "/usr/lib64/python2.7/site-packages/scrapy/crawler.py", line 285, in start
reactor.run(installSignalHandlers=False) # blocking call
File "/usr/lib64/python2.7/site-packages/twisted/internet/base.py", line 1243, in run
self.mainLoop()
File "/usr/lib64/python2.7/site-packages/twisted/internet/base.py", line 1252, in mainLoop
self.runUntilCurrent()
--- ---
File "/usr/lib64/python2.7/site-packages/twisted/internet/base.py", line 878, in runUntilCurrent
call.func(*call.args, **call.kw)
File "/usr/lib64/python2.7/site-packages/scrapy/utils/reactor.py", line 41, in __call__
return self._func(*self._a, **self._kw)
File "/usr/lib64/python2.7/site-packages/scrapy/core/engine.py", line 135, in _next_request
self.crawl(request, spider)
File "/usr/lib64/python2.7/site-packages/scrapy/core/engine.py", line 210, in crawl
self.schedule(request, spider)
File "/usr/lib64/python2.7/site-packages/scrapy/core/engine.py", line 216, in schedule
if not self.slot.scheduler.enqueue_request(request):
File "/usr/lib64/python2.7/site-packages/scrapy/core/scheduler.py", line 57, in enqueue_request
dqok = self._dqpush(request)
File "/usr/lib64/python2.7/site-packages/scrapy/core/scheduler.py", line 86, in _dqpush
self.dqs.push(reqd, -request.priority)
File "/usr/lib/python2.7/site-packages/queuelib/pqueue.py", line 33, in push
self.queues[priority] = self.qfactory(priority)
File "/usr/lib64/python2.7/site-packages/scrapy/core/scheduler.py", line 114, in _newdq
return self.dqclass(join(self.dqdir, 'p%s' % priority))
File "/usr/lib/python2.7/site-packages/queuelib/queue.py", line 142, in __init__
self.size, = struct.unpack(self.SIZE_FORMAT, qsize)
struct.error: unpack requires a string argument of length 4

安装步骤参考：
http://blog.csdn.net/shiyong1949/article/details/78212971?locationNum=10&fps=1