如何将Xcode指向旧的SDK，以便可以用作“基本SDK”？

Question

My Mac's Setup:

Volume A :
OS X 10.8
Xcode 4.5 or later - 10.6 SDK IS NOT available as Base SDK

Volume B :
OS X 10.7
Xcode 4.3.3 - 10.6 SDK IS available as Base SDK

Volume C :
OS X 10.6
Xcode 4.2 - 10.6 SDK IS available as Base SDK

---

On Volume A, I have installed Xcode 4.5, which does not include the 10.6 SDK as an available "Base SDK" in my Build Targets' Build Settings.

I have a separate 10.6 volume and 10.7 volume on this hard drive - both of which have Xcode installed, and both of which allow me to select the 10.6 SDK as a Base SDK in my Xcode Build Targets' Build Settings.

I know that I have the 10.6 SDK installed on Volume C (at /Developer/SDKs from an older Xcode installation).

How can I point Xcode on Volume A to the 10.6 SDK which lives on Volume C?

Answer 1

You'll need to add a symlink to the old SDK (this is generally easier than copying).

cd /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs
ln -s /path/to/old/SDK .

This works fine back to 10.5. Beyond that things get a little more complicated...

While there's no promise in future versions of Xcode that this will be supported, I've chatted with the Xcode team about it and they don't seem keen on changing it anytime soon.

Personally I often keep /path/to/old/SDK in a top-level directory called /SDKs. That way every time I upgrade it's easy to fix everything up.

EDIT: I have a fix-xcode script that simplifies re-applying this fix every time Xcode upgrades.

---

UPDATE: In modern versions of Xcode (7.3+) to use older SDKs edit MinimumSDKVersion here:

/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Info.plist

Answer 2

Wrong approach. You don't "point" Xcode at an SDK. Instead you will have better luck copying the SDK into the appropriate "SDKs" folder for the Xcode installation. In modern Xcode installations this is usually:

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

Copy the SDK in there, quit and restart Xcode and see what you find.

(reading the other answer here I think that symbolic linking might be an option if you are dead-set on keeping the original SDK elsewhere)

Answer 3

Why not just symbolic link the SDK's? "ln -s"? If that doesn't work there's going to be some plist hacking required.

Answer 4

通过浏览到较早版本的Xcode.App/Developer/platforms并将iOS 6.1 SDK复制到XCode 5的同一文件夹中来解决。