Reminder to SAP Cloud Platform SDK for iOS developers (and Xcode developers in general): wait to upgrade your Xcode, until framework providers have provided compatible binaries.
In the Xcode 10.2 case, SAP expects this to take a few days to work though the build & release process.
Fingers-crossed, with ABI compatibility in Swift 5, this may be nearly the last time we need to worry about this! Until then, please wait a few days for the Xcode upgrade.
If you have already upgraded Xcode to 10.2, you can download Xcode 10.1 from the Downloads section at developers.apple.com. Rename the app bundle, and you can run the two versions side-by-side.