Xcode 8 with older Base SDK

Question

I\'m running into compatibility issues for some external frameworks I\'m using in my project. Is there a way to change the Base SDK on Xcode 8? Currently in the project sett

Answer 1

My original answer, although it worked with Xcode 8, for some strange reason which is not worth explaining, no longer works with Xcode 9 on a particular client's old project. So I've been using an alternative workflow which is really not too bad.

To work on this project, I open it in both the older Xcode, which can build it with the required SDK, and in a recent Xcode. I put the old Xcode window in the background and do my work in the recent Xcode. When I am ready to test changes, I do a File > Save All (⌥⌘S), then switch to the old Xcode and Build (⌘B). When the build is done, I switch back to the recent Xcode and Product > Perform Action > Run without Building (⌃⌘R). Because the dSYM file format has not changed, breakpoints work as expected.

The advantages are that no hacking of Xcode is required, and the only thing I need to remember about the old Xcode (Xcode 3 in my case) is, mercifully: ⌘B.

One little warning: In this particular project's Target, in Build Settings, it has a custom Build Products Path. This is typical of the way Mac apps were built years ago. To ensure that both of your Xcodes are working with the same product, if your old and recent Xcodes straddle the version which changed the default Build Products Path, you may need to set Build Products Path.

The workflow could probably be made even easier by scripting the xcodebuild and xcode-select command line tools, but this is good enough. With Apple's announcement at this year's WWDC about support for 32-bit Mac apps going away during the next two years, my client has some tough decisions ahead in any case.

Answer 2

Starting with Xcode 7.3, in addition to copying in the SDK, you must also edit a certain Info.plist file, as described here for macOS in the post by agx. It looks like there is a similar file for iOS, at

Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Info.plist

Try changing the value of MinimumSDKVersion in there from 10.0 to whatever SDK version you want.

I've not tried this with iOS, but, using this workaround, I was just able to build a macOS target with macOS 10.6 using Xcode 8.0 (8A218a) (the "GM").

UPDATE

The hack described above stopped working for me in Xcode 9. If you want to use Xcode 9+, see my more recent answer dated Nov 22, 2017.

Answer 3

You just have to change the "Deployment Target" settings. You basically use the latest available SDK as base SDK but select a target OS X version. Of course it depends on why you want to use an older SDK?