Xcode Version 11.0 beta 6 (11M392q) - crashing

Since WWDC I've been anxious to take SwiftUI for a test flight. So after clearing out enough room on the SSD in my MBAir and installing Catalina (v10.15 Beta (19A536g)) over a virgin install of Mojave on a new APFS volume and creating a new user account (no migration) I installed Xcode Version 11.0 beta 6 (11M392q) and began the tutorials found here...

https://developer.apple.com/tutorials/swiftui/creating-and-combining-views

I completed the first "Creating and Combining Views" with not so much as a bump and could not help but be impressed by the streamlined SwiftUI workflow. Bouyed with optimism I launched into the second tutorial, found here...

https://developer.apple.com/tutorials/swiftui/building-lists-and-navigation

and that is where the balloon burst. I have spent hours trying to determine what it is in Apple's code that is making xcode bark with a seemingly randow error message almost every time I run the preview, which would be maddening enough but every once in a dogs age it works! And this is Apple's code. I've done nothing to the code. I've only opened the projects -"Complete" and "StartingPoint" and clicked to RESUME the Preview.

Is it me? Has anyone figured out how to get these tutorials to behave? How can I get the version they ran at WWDC...or did they edit out the crashes?

I am seeing the same but only in the Starting code, the Complete works for me in Preview. I'm running beta 5 though. I'll try beta 6 ...


Edit: Upgraded to Beta 6 with similar results. I have submitted two preview debug reports through feedback.

Same here. 😟 It doesn't even auto-complete

Xcode Version 11.0 beta 6 (11M392q) - crashing
 
 
Q