Dropping the 10.5 SDK is also a problem for software which does not use Xcode for the build system, but expects (perhaps foolishly) for specific SDKs to be in place.
To add the SDK back, I re-installed the MacOSX10.5.pkg
from the Xcode 3.2.6 download. It is in a hidden folder named "Packages" on the disk image. After mounting the .dmg file, you can open it from the command line with open /Volumes/Xcode and iOS SDK/Packages/
. When installing the package, choose change install location and option-click on the drive you want to install to, so that you can specify a folder. The target folder should be /Developer
or the base of your Xcode 4 install if you have put it in a non-standard location.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…