Adding the `SwiftSpreadsheet` package by branch with SPM works. However, if you select a version number, e.g. "Up to Next Minor Version", an error message appears in a dialog. <img width="761" alt="Screen Shot 2021-12-10 at 1 39 08 PM" src="https://user-images.githubusercontent.com/356623/145644615-ecce75e9-9b50-4b17-b5d6-4152bdb7b6e8.png"> I believe the resolution is to publish a release on GitHub.