我无法理解安装失败的原因:
pkerur@ubuntu:~$ rails --version
Rails 3.2.3
pkerur@ubuntu:~$ uname -a
Linux ubuntu 3.2.0-24-generic #38-Ubuntu SMP Tue May 1 16:21:07 UTC 2012 i686 i686 i386 GNU/Linux
pkerur@ubuntu:~$ ruby --version
ruby 1.9.3p0 (2011-10-30 revision 33570) [i686-linux]
pkerur@ubuntu:~$ sudo gem install paperclip
ERROR: Error installing paperclip:
paperclip requires Ruby version >= 1.9.2.
pkerur@ubuntu:~$