How to I add the Google Drive API to my iPhone project to I can use it?
So far, I have dragged the GTL project into my current app project (so that it is nested unde
I struggled with this error message as well. This is how I solved it:
Make sure you have added the folder for the service that you are using under GTLSource/Common/ (e.g., add the Drive folder for GoogleDrive).
Under GTL.xcodeproj (that you have already added to your workspace) find the GTLSource folder and drag it to your main project (Golf in your case). Done!
Now you can remove references to the GTL.xcodeproj that you have added to the workspace.
With this approach, you don't even need to add the libraries (so remove them from the list of linked libraries if you have added them).
The Google API documentation is nothing like Apple's documentation (it's not good).
I should also mention that I'm building an app for iOS and not MacOSX, but this should work for OSX as well.