Xcode shows an error when trying to print an object with
error: Couldn't materialize struct: size of variable <varName> disagrees with the ValueObject's size
Errored out in Execute, couldn't PrepareToExecuteJITExpression
Are you sure you are not in "Release mode"?
If you want to see variable values you have to be in "Debug mode" (click on your project name on the top left corner near start/stop buttons, then "Edit scheme...", then "Run" settings, then "Info" tab, then "Build Configuration". Here set "Debug". If it was on "Release" that's the matter you saw all nils).