The “Swift Language Version” (SWIFT_VERSION) build setting error with project in Objective C

Question

So i just went to build my app after adding in core data to update my app to store and fetch some information and i got this error. (I am using XCode 9.2)

The “Swift Language Version” (SWIFT_VERSION) build setting must be set to a supported value for targets which use Swift. This setting can be set in the build settings editor.

Now whats confusing me is this in an Objective C app and surely the swift version shouldn't matter. I have browsed some threads on here stating that i need to update build setting to Swift 3.0 or to set values to Yes then back to No, however i have none of these fields when i search for Swift in the search bar.

Is this just a bizarre bug or have i mistakenly added some swift code?

Any ideas would help, thanks.

Answer 1

I experienced this exact same issue after adding Core Data to an Objective-C framework I was working on.

I discovered that the reason I was getting the "Swift Language Version" warning was that the Code Generation language in the .xcdatamodel defaulted to Swift. Once I changed this back to Objective-C, the warning went away.

You can find this property in the File Inspector when you have the .xcdatamodel selected in the Project Navigator.