Rails的3.0.0.beta安装问题：找不到可执行轨

Question

我试图安装3.0.0.beta，我遇到这个问题，导轨：

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$ 

任何线索，到这里发生了什么？

Answer 1

RubyGems的升级和清理后，您需要：

gem install railties --pre 

Answer 2

尝试

sudo gem update --system 

因为这并不算什么，尝试

sudo gem cleanup 

然后重新安装。

Answer 3

sudo gem install railties --pre