I had to do this myself several times to isolate a macOS bug: duplicate the Xcode project, then start reducing the code and test if the issue still happens, and if it does, make a duplicate of the duplicate so that I can go back to it in case my next reduction solves the issue. Keep repeating until you have a tiny project that reproduces it. It may take several hours (even the whole day) and test your patience to the extreme, but sometimes there's no other way.
Topic:
UI Frameworks
SubTopic:
AppKit
Tags: