我正在尝试让omniauth-facebook gem在我的Rails 2.3.4应用程序中运行，但这取决于omniauth-oauth2，而rack ~> 1.2依赖于[Dev]> require 'omniauth-facebook'
Gem::LoadError: can't activate rack (~> 1.2, runtime) for ["oauth2-0.8.0", "omniauth-oauth2-1.1.0", "omniauth-facebook-1.4.1"], already activated rack-1.0.1 for []
from /Library/Ruby/Site/1.8/rubygems.rb:233:in `activate'
from /Library/Ruby/Site/1.8/rubygems.rb:249:in `activate'
from /Library/Ruby/Site/1.8/rubygems.rb:248:in `each'
from /Library/Ruby/Site/1.8/rubygems.rb:248:in `activate'
from /Library/Ruby/Site/1.8/rubygems.rb:249:in `activate'
from /Library/Ruby/Site/1.8/rubygems.rb:248:in `each'
from /Library/Ruby/Site/1.8/rubygems.rb:248:in `activate'
from /Library/Ruby/Site/1.8/rubygems.rb:249:in `activate'
from /Library/Ruby/Site/1.8/rubygems.rb:248:in `each'
from /Library/Ruby/Site/1.8/rubygems.rb:248:in `activate'
from /Library/Ruby/Site/1.8/rubygems/custom_require.rb:35:in `require'
from /Library/Ruby/Gems/1.8/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:156:in `require'
from /Library/Ruby/Gems/1.8/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:521:in `new_constants_in'
from /Library/Ruby/Gems/1.8/gems/activesupport-2.3.4/lib/active_support/dependencies.rb:156:in `require'
from (irb):1
。当我在我的应用程序中尝试要求它时，我收到此错误消息：
actionpack此错误是由rack ~> 1.0.0 2.3.4需要omniauth-oauth2这一事实引起的，因此当~> 1.2需要1.0.1，omniauth-facebook时已经被加载并且它已经爆炸了
如何在不升级Rails版本的情况下解决此问题？ （会使用较旧版本的{{1}}吗？）