使用yum命令式报错：thread.error: can't start new thread。
错误具体内容为：
[root@lxy.me]# yum update
Loaded plugins: fastestmirror
Determining fastest mirrors
Traceback (most recent call last):
File "/usr/bin/yum", line 29, in ?
yummain.user_main(sys.argv[1:], exit_code=True)
File "/usr/share/yum-cli/yummain.py", line 309, in user_main
errcode = main(args)...
