“Gem::RemoteFetcher::UnknownHostError” while installing Rails version 3.2.15

Question

i\'ve successfully installed rails 3.2.15 on a live ubuntu usb with data persistence before.

now that i\'ve become used to the os (Ubuntu 12.04 LTS), i\

Answer 1

I had the same problem: Ubuntu 12.04, ruby 2.1.0 trying to install latest rails (4.0.x). Doing gem install rails I was getting same error. What I did:

• update rubygem: gem update --system and it went from 2.2.0 to 2.2.2
• located outdated gems (gem outdated) and got several outdated: bigdecimal (1.2.3 < 1.2.5), minitest (4.7.5 < 5.2.3), psych (2.0.2 < 2.0.4), rake (10.1.0 < 10.1.1), rdoc (4.1.0 < 4.1.1), test-unit (2.1.0.0 < 2.5.5)
• updated gems with gem update
• Sucessfully installed rails with gem install rails --no-ri --no-rdoc

At rails -v I got Rails 4.0.3.