swiftpm-xcode-bug

Xcode SwiftPM integration bug with "Missing package product"

Steps to reproduce

1. Open XcodeBug.xcodeproj in the master branch, build and run, all will succeed.
2. Without closing Xcode, check out test-branch and try to build.
3. You'll see this:

The only work around that helps with this bug is to completely close Xcode and reopen the project. This also causes all SwiftPM dependencies to be re-resolved in the project, which can take some time if you have multiple dependencies.