Full Xcode application which can take up-to 40GB of disk space is not necessary for building VeraCrypt, rather the CommandLineTools for XCode are sufficient which only take few gigabytes. Instead of hardcoding the SDK location, use xcrun --show-sdk-path to support also the CommandLineTools instance. The reason for switching the logic for the XCode version is because the xcodebuild will not report a correct XCode version for the CommandLineTools, thus it can't be relied for whether to use the -Wl,-ld_classic flags. Instead, we can just check the ld version in use in the active developer directory, and see whether we are using dyld (the new) or ld64 (the old).