Backward compatibility for iOS build SDKs

Question

I would like to run old application which has a support of iOS 5.0 and less. It has a deployment target 5.0. The thing is that:

I have upgraded system to Yosemite OS 10.10 and lowest Xcode version I have 5.0. Now when I look on base SDK and I see below picture.

As you see the least build SDK shown s iOS 7.0. No other lower version is there.

I heard or I read some where that you can also use lower version SDK here. By copying SDKs to some where or any other means. I would like to know a better approach here.

Edit:

I have a requirement of one application which was developed in Xcode 4.6 for iOS 5.0. So that just to check that application flow I need to download Xcode 4.6. Is it so? Can we don't include older SDKs in newer version of Xcode?

Answer 1

You should not attempt to build your application with an old version of Xcode. The only version of Xcode supported on Yosemite is Xcode 6.1, which only ships with the iOS 8 SDK. You should build for the latest SDK, and set the Deployment Target to iOS 5 if you want your code to run there (by degrading gracefully using NSClassFromString and respondsToSelector: checks)