原来我需要将10.6 SDK复制到XCode应用程序：

It turned out that I needed to copy the 10.6 SDK to the the XCode app:

我发现一个旧版本，并拖动了一个副本：

I found an old version and dragged a copy of:

/Developer/SDKs/MacOSX10.6。 sdk

至：

/Applications/Xcode.app/Contents/Developer /Platforms/MacOSX.platform/Developer/SDKs

现在它位于MacOSX10.7.sdk和MacOSX10.8.sdk

It now sits along side the MacOSX10.7.sdk and MacOSX10.8.sdk

重新启动XCode后，请记住进入构建设置并将Base SDK设置为OS X 10.6

After restarting XCode, remember to go into build settings and set the Base SDK to OS X 10.6

请参阅： http://***.com/a/11705378/123777