rails server
启动之前运行的 rails 应用程序时出现以下错误。
/home/ganesh/.rvm/gems/ruby-1.9.3-p327/gems/actionpack-3.2.5/lib/action_dispatch.rb:35:in `require': cannot load such file -- rack (LoadEr
ror)
from /home/ganesh/.rvm/gems/ruby-1.9.3-p327/gems/actionpack-3.2.5/lib/action_dispatch.rb:35:in `<top (required)>'
from /home/ganesh/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.5/lib/rails/commands/server.rb:3:in `require'
from /home/ganesh/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.5/lib/rails/commands/server.rb:3:in `<top (required)>'
from /home/ganesh/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.5/lib/rails/commands.rb:49:in `require'
from /home/ganesh/.rvm/gems/ruby-1.9.3-p327/gems/railties-3.2.5/lib/rails/commands.rb:49:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'
如何消除此错误。帮我。