How to add base SDK for 10.5 in xCode 4

Question

I\'ve installed xCode 4 last night and tried to compile a software which should support 10.5 and above OSs.

It gave the error message \"Base SDK missing\". I found t

Answer 1

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.