I'm using a GoogleMaps pod in my xcode workspace.
I followed https://developers.google.com/maps/documentation/ios-sdk/start#step_1_get_the_latest_version_of_xcode for setup about a year ago.
I've got a new computer and when I open my workspace project I get
Podfile.lock: No such file or directory
Manifest.lock: No such file or directory
"The sandbox is not in sync with the Podfile.lock. Run pod install or update your Cocoapods installation.
! The dependency 'GoogleMaps' is not used in any concrete target.
By reinstalling cocoapods on your system, I guess you downloaded a newer version of it, so the Podfile syntax changed a little bit, what you're missing is the target, you can read more about this here
So in your case it would be something like this:
source 'https://github.com/CocoaPods/Specs.git' target 'App target' pod 'GoogleMaps'
pod install after that and that's all.