It took me several tries and some research to figure out how to follow the spm setup instructions

Step 1 may be a bit confusing to people as the default hierarchy is ArkanaKeys > ArkanaKeys. The instructions say to select the ArkanaKeys folder, without being specific for which one (it is of course the inner one).

Step 3 was hard to follow because there appears to be an issue that your local package you added above does not show up in the list to choose from unless you quit and reload xcode.