我试图在终端中运行以下命令：
scrapy shell www.example.com
而不是期望的结果，我得到：
...
File "/usr/local/lib/python2.7/site-packages/Scrapy-1.3.0-py2.7.egg/scrapy/shell.py", line 115, in fetch
reactor, self._schedule, request, spider)
File "/usr/local/lib/python2.7/site-packages/Twisted-16.7.0rc1-py2.7-macosx-10.11-x86_64.egg/twisted/internet/threads.py", line 122, in blockingCallFromThread
result.raiseException()
File "<string>", line 2, in raiseException
有人可以帮助我让scrapy shell命令正常工作吗？