安装ffi（1.1.2）时发生错误，并且Bundler无法继续

Question

在Rails 3.0项目中运行OSX Mountain Lion。

当试图更新我的捆绑宝石在Rails项目中，我得到以下errror：

An error occured while installing ffi (1.1.2), and Bundler cannot continue. 
Make sure that `gem install ffi -v '1.1.2'` succeeds before bundling. 

ERROR: Error installing ffi: 
    ERROR: Failed to build gem native extension. 

     /Users/victorstan/.rvm/rubies/ruby-1.9.2-p320/bin/ruby extconf.rb 
checking for ffi.h... *** extconf.rb failed *** 
Could not create Makefile due to some reason, probably lack of 
necessary libraries and/or headers. Check the mkmf.log file for more 
details. You may need configuration options. 

... 

You have to install development tools first. 

我安装的XCode以及命令行工具。

Answer 1

你应该使用：

sudo ln -s /usr/bin/gcc /usr/bin/gcc-4.2 

又见Issue with installing ImageMagick and rmagick on Mountain Lion和https://gist.github.com/1860511。

Answer 2

如果您重新安装Xcode的命令行工具，它应该可以正常工作。这里是链接： https://developer.apple.com/downloads/index.action?=Command%20Line%20Tools%20%28OS%20X%20Mountain%20Lion%29