Ruby gem错误安装机架式安装+ Rails

Question

我想安装Rails 3.0 Beta但遇到似乎是依赖性错误:

$: sudo gem install rack-mount
Successfully installed rack-mount-0.5.1
1 gem installed
Installing ri documentation for rack-mount-0.5.1...
Installing RDoc documentation for rack-mount-0.5.1...



$: sudo gem install rails --prerelease
ERROR:  Error installing rails:
    actionpack requires rack-mount (~> 0.4.0, runtime)

为什么无法识别已安装机架安装？

Answer 1

正如在评论中指出这里,你需要rack-mount在确切版本0.4.0.使用以下命令安装:

gem install rack-mount -v 0.4.0