gem install rails

May be it is a question of rem or ruby,but I need your help. When I use gem install rails,it fails.But I use the same command,it passed in another computer. OK. I use    hector@hector-laptop:~$ sudo gem install rails --no-rdoc --no-ri The result:    source not present in cache

But I try to use wget to get Anything is okay. Here is my environment: gem environment RubyGems Environment:   - RUBYGEMS VERSION: 1.1.0 (1.1.0)   - RUBY VERSION: 1.8.6 (2007-09-24 patchlevel 111) [i486-linux]   - INSTALLATION DIRECTORY: /usr/lib/ruby/gems/1.8   - RUBY EXECUTABLE: /usr/bin/ruby1.8   - RUBYGEMS PLATFORMS:     - ruby     - x86-linux   - GEM PATHS:      - /usr/lib/ruby/gems/1.8   - GEM CONFIGURATION:      - :update_sources => true      - :verbose => true      - :benchmark => false      - :backtrace => false      - :bulk_threshold => 1000   - REMOTE SOURCES:      -

Sounds like you have different sources on the two machines. There was talk recently about where best to source for rails, but I don't remember quite what the answer was. Anyway, you want to run this on both machines: $ gem sources

Then you can add missing sources (like the one gem is complaining about above, with: $ gem source <gem source location>