问题：
执行 yum install -y zabbix-server-MySQL zabbix-web-mysql zabbix-agent mariadb-server
命令下载安装包的时候遇到了下面的问题
Traceback (most recent call last):
File "/usr/libexec/urlgrabber-ext-down", line 75, in <module>
main()
File "/usr/libexec/urlgrabber-ext-down", line 61, in main
fo = PyCurlFileObject(opts.url, opts.filename, opts)
File "/usr/lib/python2.7/site-packages/urlgrabber/grabber.py", line 1258, in __init__
self._do_open()
File "/usr/lib/python2.7/site-packages/urlgrabber/grabber.py", line 1589, in _do_open
self._do_grab()
File "/usr/lib/python2.7/site-packages/urlgrabber/grabber.py", line 1723, in _do_grab
self._do_perform()
File "/usr/lib/python2.7/site-packages/urlgrabber/grabber.py", line 1517, in _do_perform
raise KeyboardInterrupt
原因：
This issue is due to a bug in the urlgrabber python script: To mitigate this issue you can edit the line 1510 from /usr/lib/python2.7/site-packages/urlgrabber/grabber.py
解决：
打开这个文件：/usr/lib/python2.7/site-packages/urlgrabber/grabber.py
找到 elif errcode in (42, 55, 56):
用 elif errcode == 42:替换