Installing paperclip plugin

I'm trying to install the paperclip plugin with the following command:

ruby script/plugin install git://github.com/thoughtbot/paperclip.git

But I'm getting some errors:

ruby script/plugin install git://github.com/thoughtbot/paperclip.git --force
svn: '/home/app/vendor/plugins' is not a working copy
/usr/lib/ruby/1.8/open-uri.rb:32:in `initialize': No such file or directory - git://github.com/thought开发者_JAVA百科bot/paperclip.git (Errno::ENOENT)
    from /usr/lib/ruby/1.8/open-uri.rb:32:in `open_uri_original_open'
    from /usr/lib/ruby/1.8/open-uri.rb:32:in `open'
    from ./script/../config/../vendor/rails/railties/lib/commands/plugin.rb:863:in `fetch_dir'
    from ./script/../config/../vendor/rails/railties/lib/commands/plugin.rb:857:in `fetch'
    from ./script/../config/../vendor/rails/railties/lib/commands/plugin.rb:856:in `each'
    from ./script/../config/../vendor/rails/railties/lib/commands/plugin.rb:856:in `fetch'
    from ./script/../config/../vendor/rails/railties/lib/commands/plugin.rb:219:in `install_using_http'
    from ./script/../config/../vendor/rails/railties/lib/commands/plugin.rb:169:in `send'
    from ./script/../config/../vendor/rails/railties/lib/commands/plugin.rb:169:in `install'
    from ./script/../config/../vendor/rails/railties/lib/commands/plugin.rb:734:in `parse!'
    from ./script/../config/../vendor/rails/railties/lib/commands/plugin.rb:732:in `each'
    from ./script/../config/../vendor/rails/railties/lib/commands/plugin.rb:732:in `parse!'
    from ./script/../config/../vendor/rails/railties/lib/commands/plugin.rb:447:in `parse!'
    from ./script/../config/../vendor/rails/railties/lib/commands/plugin.rb:463:in `parse!'
    from ./script/../config/../vendor/rails/railties/lib/commands/plugin.rb:871
    from script/plugin:3:in `require'
    from script/plugin:3

Is it because I'm using a old rails version?

I'm afraid version 1.1.2 of rails doesn't support git plugins. That version supports Subversion, and HTTP.

Though of course given github have reasonable subversion support you could try checking out using their subversion url: http://svn.github.com/thoughtbot/paperclip. Though I get the feeling you'll probably have some compatability issues.