After updating Ruby on Rails, I have the following problem

[B.Tag]

After updating Ruby on Rails, I have the following problem?

/usr/local/lib/site_ruby/1.9.1/rubygems/dependency.rb:247:in `to_specs': Could not find rails (>= 0) amongst [rubygems-update-1.8.12] (Gem::LoadError)

from /usr/local/lib/site_ruby/1.9.1/rubygems/dependency.rb:256:in `to_spec'

from /usr/local/lib/site_ruby/1.9.1/rubygems.rb:1208:in `gem'

from /usr/local/bin/rails:18:in `<main>'

:~$ sudo gem update --system

[sudo] password for b-tag: 

Latest version currently installed. Aborting.

:~$ sudo update_rubygems 

RubyGems 1.8.14 installed

== 1.8.14 / 2012-01-05

* 2 bug fixes:

  * Ignore old/bad cache data in Version

  * Make sure our YAML workarounds are loaded properly. Fixes #250.

------------------------------------------------------------------------------

RubyGems installed the following executables:

/usr/bin/gem1.9.1

Done the above steps, the result is the same

:~$ sudo gem install rails

ERROR:  Could not find a valid gem 'rails' (>= 0) in any repository

ERROR:  Possible alternatives: rails

[Xavier Noria]

Could you please ask in rubyonrails-talk? This mailing list is about
the development of Ruby on Rails itself.

Thanks.