My current workflow to have a Swift Package with a Demo is like this:
PackageFolder > DemoFolder
I have a package, with a Demo folder inside. I can open the Demo project and Drag&Drop the local PackageFolder to override the remote dependency with the local one. This allows to edit the package while inside the demo project.
With Xcode 16 this does no longer work because Xcode does not allow to drop an ancestor of the file path where the project is located. Xcode does not tell this while you drop, it just does not allow it. But it tells you thats the reason, when you try to add the local package as a dependency to the project: "The selected package cannot be a direct ancestor of the project.".
(Dropping other local packages still works, see: https://forums.developer.apple.com/forums/thread/756824)
What is the expected way to handle a package with a demo project with Xcode 16?
At least with Xcode 16 beta 5 it is possible to add the package as a local dependency to the demo project.
The following steps give me the result I need: Open Project > Package Dependencies > Add package > "Add local"
Optional for more convenience: Add package as reference: Drag&Drop folder of target from the package into Xcode 1. Action: Reference files in place 2. De-select target