Rails的3.0.0.beta安裝問題：找不到可執行軌

Question

我試圖安裝3.0.0.beta，我遇到這個問題，導軌：

justins-mac-: justinz$ ruby -v 
ruby 1.8.7 (2008-08-11 patchlevel 72) [universal-darwin10.0] 
justins-mac-justinz$ rails -help 
/Library/Ruby/Site/1.8/rubygems.rb:384:in `bin_path': can't find executable rails for rails-3.0.0.beta (Gem::Exception) 
from /usr/bin/rails:19 
justins-mac-justinz$ rails -v 
/Library/Ruby/Site/1.8/rubygems.rb:384:in `bin_path': can't find executable rails for rails-3.0.0.beta (Gem::Exception) 
from /usr/bin/rails:19 
justins-mac-justinz$ 

任何線索，到這裏發生了什麼？

Answer 1

RubyGems的升級和清理後，您需要：

gem install railties --pre 

Answer 2

嘗試

sudo gem update --system 

因爲這並不算什麼，嘗試

sudo gem cleanup 

然後重新安裝。

Answer 3

sudo gem install railties --pre