$ gem -v
1.2.0
$ sudo gem update --system
Updating RubyGems
Updating rubygems-update
Successfully installed rubygems-update-1.3.1
ERROR: While executing gem ... (NameError)
undefined local variable or method `remote_gemspecs' for #<Gem::Commands::UpdateCommand:0xb79f00bc>
$ gem -v
1.2.0
$ sudo gem update --system
Updating RubyGems
Nothing to update
$ sudo gem install rubygems-update --debug
Exception `NameError' at /usr/local/lib/ruby/site_ruby/./rubygems/command_manager.rb:134 - uninitialized constant Gem::Commands::InstallCommand
Exception `Gem::LoadError' at /usr/local/lib/ruby/site_ruby/./rubygems.rb:578 - Could not find RubyGem sources (> 0.0.1)
Exception `IOError' at /usr/local/lib/ruby/site_ruby/./rubygems/format.rb:50 - closed stream
Exception `Errno::EEXIST' at /usr/local/lib/ruby/./fileutils.rb:243 - File exists - /usr/local/lib/ruby/gems/gems/rubygems-update-1.3.1
...
Successfully installed rubygems-update-1.3.1
1 gem installed
$ cd /usr/local/lib/ruby/gems/gems/rubygems-update-1.3.1/
rubygems-update-1.3.1$ sudo ruby setup.rb
$ gem -v
1.3.1