Python scrapy运行出错报VerificationError错误，,在启动scrapy时提示

Python scrapy运行出错报VerificationError错误，,在启动scrapy时提示

在启动scrapy时提示如下错误？是crypt库版本问题？还是什么原因。。

cffi.ffiplatform.VerificationError: importing
'/usr/local/lib/python2.7/site-packages/cryptography/_Cryptography_cffi_a269d620xd5c405b7.so':
/usr/local/lib/python2.7/site-packages/cryptography/_Cryptography_cffi_a269d620xd5c405b7.so:
undefined symbol: EC_GROUP_new_curve_GF2m

环境：

CentOS release 6.6
Python2.7

pip install pyOpenSSL==0.13

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