无法使用Xcode 4.3安装autotest-fsevent gem

Question

在更新到Xcode 4.3 (删除了旧版本的Xcode)后，我无法安装autotest-fsevent gem。命令行工具是通过Preferences > Downloads > Components选项卡安装的。

osx 10.7.3、rvm 1.10.2、ruby 1.9.3-rc1、捆绑包1.0.22

$ bundle

Installing autotest-fsevent (0.2.7) with native extensions 
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.

    /Users/doc/.rvm/rubies/ruby-1.9.3-rc1/bin/ruby extconf.rb 
extconf.rb:36:in `<main>': Xcode not found - see README for assistance (RuntimeError)


Gem files will remain installed in /Users/doc/.rvm/gems/ruby-1.9.3-rc1@global/gems/autotest-fsevent-0.2.7 for inspection.
Results logged to /Users/doc/.rvm/gems/ruby-1.9.3-rc1@global/gems/autotest-fsevent-0.2.7/ext/fsevent/gem_make.out
An error occured while installing autotest-fsevent (0.2.7), and Bundler cannot continue.
Make sure that `gem install autotest-fsevent -v '0.2.7'` succeeds before bundling.

自述文件简单地指出Xcode是必需的。

我似乎选择了正确的Xcode.app：

$ xcode-select -print-path
/Applications/Xcode.app/Contents/Developer

还有人有这个问题吗？有什么办法解决这个问题吗？

Answer 1

事实证明，Xcode路径在gem文件中是硬编码的：

ext/fsevent/extconf.rb：

...
  elsif File.exists?('/Developer/Applications/Xcode.app')
    `CFLAGS='-isysroot /Developer/SDKs/MacOSX#{SDK_VERSION}.sdk -mmacosx-version-min=#{SDK_VERSION}' /usr/bin/gcc -framework CoreServices -o "#{GEM_ROOT}/bin/fsevent_sleep" fsevent_sleep.c`
    raise "\e[1;31mCompilation of fsevent_sleep binary failed - see README for assistance\e[0m" unless File.executable?("#{GEM_ROOT}/bin/fsevent_sleep")
...

Xcode4.3现在作为应用程序安装在/Applications中。另一位github用户(fxposter)发现了同样的问题，并在我之前的几个小时发出了一个pull request。建议的更改已经合并到gem中，并且v0.2.8已经发布。