carthage build

$carthage update --platform macOS
results in:

*** Skipped building Then due to the error:
Dependency "Then" has no shared framework schemes for any of the platforms: Mac

If you believe this to be an error, please file an issue with the maintainers at https://github.com/devxoul/Then/issues/new

Using carthage 0.34, Swift 5, xcode 10.2