`build_extensions'：错误：无法构建gem本机扩展。 （宝石::安装:: ExtensionBuildError）

Question

在OS X Lion中试图启动Rails服务器出现错误

Could not find json-1.5.4 in any of the sources 
Run `bundle install` to install missing gems. 

如果我再运行

bundle install json 

我收到以下错误时，

Installing json (1.5.4) with native extensions /Library/Ruby/Site/1.8/rubygems/installer.rb:556:in `build_extensions': ERROR: Failed to build gem native extension. (Gem::Installer::ExtensionBuildError) 

     /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby extconf.rb 
mkmf.rb can't find header files for ruby at /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/ruby.h 


Gem files will remain installed in /Applications/RubyApps/skatemyspot/json/ruby/1.8/gems/json-1.5.4 for inspection. 
Results logged to /Applications/RubyApps/skatemyspot/json/ruby/1.8/gems/json-1.5.4/ext/json/ext/parser/gem_make.out 
    from /Library/Ruby/Site/1.8/rubygems/installer.rb:509:in `each' 
    from /Library/Ruby/Site/1.8/rubygems/installer.rb:509:in `build_extensions' 
    from /Library/Ruby/Site/1.8/rubygems/installer.rb:180:in `install' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.18/lib/bundler/source.rb:101:in `install' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.18/lib/bundler/rubygems_integration.rb:78:in `preserve_paths' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.18/lib/bundler/source.rb:91:in `install' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.18/lib/bundler/installer.rb:58:in `run' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.18/lib/bundler/rubygems_integration.rb:93:in `with_build_args' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.18/lib/bundler/installer.rb:57:in `run' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.18/lib/bundler/installer.rb:49:in `run' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.18/lib/bundler/installer.rb:8:in `install' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.18/lib/bundler/cli.rb:220:in `install' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.18/lib/bundler/vendor/thor/task.rb:22:in `send' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.18/lib/bundler/vendor/thor/task.rb:22:in `run' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.18/lib/bundler/vendor/thor/invocation.rb:118:in `invoke_task' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.18/lib/bundler/vendor/thor.rb:263:in `dispatch' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.18/lib/bundler/vendor/thor/base.rb:386:in `start' 
    from /Library/Ruby/Gems/1.8/gems/bundler-1.0.18/bin/bundle:13 
    from /usr/bin/bundle:19:in `load' 
    from /usr/bin/bundle:19 

我在nokogiri - ERROR: Failed to build gem native extension上看到了答案，但是我已经运行了Xcode 4.3.2。

任何想法？谢谢

Answer 1

对于OS 10.7 + XCode4.3只打开Xcode首选项，选择 “下载”按钮，选择下载的“组件”选项卡，突出显示 “命令行工具”，然后按安装按钮。