Ansible [WARNING]: Skipping plugin 问题

系统：CentOS Linux release 7.6.1810 (Core)
Python：Python 2.7.5
Ansible：ansible 2.9.7
在执行playbook的时候总是有下面这样的WARNING

[root@master tasks]# ansible-playbook test.yaml         
[WARNING]: Skipping plugin (/usr/lib/python2.7/site-packages/ansible/plugins/connection/httpapi.py) as it seems to be invalid: from_buffer() cannot return the address of the raw string within a str or
unicode or bytearray object
[WARNING]: Skipping plugin (/usr/lib/python2.7/site-packages/ansible/plugins/connection/vmware_tools.py) as it seems to be invalid: from_buffer() cannot return the address of the raw string within a str or
unicode or bytearray object
[WARNING]: Skipping plugin (/usr/lib/python2.7/site-packages/ansible/plugins/callback/foreman.py) as it seems to be invalid: from_buffer() cannot return the address of the raw string within a str or unicode
or bytearray object
[WARNING]: Skipping plugin (/usr/lib/python2.7/site-packages/ansible/plugins/callback/grafana_annotations.py) as it seems to be invalid: from_buffer() cannot return the address of the raw string within a
str or unicode or bytearray object
[WARNING]: Skipping plugin (/usr/lib/python2.7/site-packages/ansible/plugins/callback/hipchat.py) as it seems to be invalid: from_buffer() cannot return the address of the raw string within a str or unicode
or bytearray object
[WARNING]: Skipping plugin (/usr/lib/python2.7/site-packages/ansible/plugins/callback/nrdp.py) as it seems to be invalid: from_buffer() cannot return the address of the raw string within a str or unicode or
bytearray object
[WARNING]: Skipping plugin (/usr/lib/python2.7/site-packages/ansible/plugins/callback/slack.py) as it seems to be invalid: from_buffer() cannot return the address of the raw string within a str or unicode
or bytearray object
[WARNING]: Skipping plugin (/usr/lib/python2.7/site-packages/ansible/plugins/callback/splunk.py) as it seems to be invalid: from_buffer() cannot return the address of the raw string within a str or unicode
or bytearray object
[WARNING]: Skipping plugin (/usr/lib/python2.7/site-packages/ansible/plugins/callback/sumologic.py) as it seems to be invalid: from_buffer() cannot return the address of the raw string within a str or
unicode or bytearray object

解决方法：pip install cryptography -U
升级后cryptography版本：cryptography (2.9.2)