error: Unable to resolve build file: XCBCore.Build

Question

error: Unable to resolve build file: XCBCore.BuildFile (missingTargetProductReference("3bf83096e50de72a94699e9afc1133ebe3512682230d04680075c283a974e273")) (in target 'MyTarget')

Xcode 10 is giving this error immediately when trying to build our project. It's not immediately clear what is causing it.

How can I resolve it?

Answer 1

This was the culprit for my experience of the same error:

After setting the correct version of Command Line Tools (i.e., Xcode 10.2.1; see below) on my system, the error went away!

Answer 2

I have the same problem. Because a folder not upload to Git server, git not allow upload empty folder, then I create a folder in project folder, and it work well. missing folder

Answer 3

I had correct Command Line Tools and cleaning did nothing for me.

While resolving a merge conflict, A Group named "Recovered References" had appeared in my project navigator. Probably due to a mistake I made during merging. The Group was empty and deleting it fixed my problem.

Answer 4

If you have a File Group which is backed by a physical folder and that physical folder has been deleted then you will get the same error "Unable to resolve build file: XCBCore.BuildFile". In my case the physical folder has been removed (because I removed all "real" files from it) and in XCode group there was still one external project linked.

Solution: - created a new group (without a folder) in XCode - Moved external project reference there. - rebuilt the project

Error gone.

Answer 5

Just Restarted my Xcode and the problem went away

Answer 6

For XCode 10 Beta: Problem occurs when I have two workspaces open that share the same project directories. Solution was

Short version

1. Shut down all but one workspaces
2. exit XCode and reopen XCode
3. XCode > Product > Clean Build Folder

Longer version

1. Shut down all but one workspace
2. XCode > Preferences > Locations > Derived Data > goto directory ~/Library/Developer/Xcode/DerivedData
3. Clear out subdirectories from DerivedData
4. exit XCode and reopen XCode
5. XCode > Product > Clean Build Folder

Thanks to @aferriss answer for the clue.