I can't work out how to debug a preview in Xcode 13.

Documentation for Xcode 11 and Xcode 12 has conflicting advice like

• right click the run button and you'll get a menu
• control/command/option click run
• long click the run

I've tried it all - and put breakpoints on almost every line of code in my preview / view / init functions - and however I hit run, it just... runs... - so I see the preview, but no breakpoints are hit - no print statements come out in the console - no cool expanded ui display appears - and no menus appear.

Any ideas?