在Ubuntu12.04上添加PPA源时报错

dsfsfs

　　在Ubuntu12.04上添加PPA源时报错。
　　Whenever I try to add a repository via the command line, I get the following error message:
　　

　　Traceback (most recent call last):
　　File "/usr/bin/add-apt-repository", line 125, in <module>
　　ppa_info = get_ppa_info_from_lp(user, ppa_name)
　　File "/usr/lib/python2.7/dist-packages/softwareproperties/ppa.py", line 80, in get_ppa_info_from_lp
　　curl.perform()
　　pycurl.error: (60, 'server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none')
　　

　　google之后按照下面的命令解决了。
This kind of problem can be caused when there is something wrong with the central authority certificates on your system. These certificates are used to establish a chain of trust from someone Ubuntu or Mozilla trusts to a particular site when https: is used. The chain of trust starts with certificates installed as part of your Ubuntu system.
The problem might ordinarily manifest itself when you use a web browser to make a secure connection to a web site. In this case add-apt-repository is using the https: protocol to securily add a repository and its authentication keys. The current Ubuntu ppa repositories require a chain of trust from MakeDaddy.com to Canonical. If you use Firefox to browse to the same repositories using https: you will probably see an error rather than a closed padlock for the site, and clicking that will provide error messages indicating that the chain of trust cannot be determined.
Enter the following to reinstall the central authority certificates:
sudo apt-get install --reinstall ca-certificatesAnother helpful command for this:
sudo update-ca-certificates　　

　　先用了 update-ca-certificates。不好使。
　　apt-get install --reinstall ca-certificates 之后问题解决了。
　　

　　这问题也就是安装PepperFlash ppa源才发现的。