Same issue remains in simulator in Xcode 11.3.1.

May we presume you filed a bug?

"Go to the Options tab under Run Action and choose Use Terminal for Console" I don't see it and none of my co-workers can see it. We've been looking for it really hard since this feature was announced (Xcode 11.4) but none of as can find it. Is it really there?

The limitation referred to in the other answer is now lifted. Swift Packages can now include resources and frameworks.

What I found is that when you manipulate the view controllers during the transition from compact to regular, you need to put a short delay on that manipulation so that the runloop has a chance to complete first.

I agree. The idea of two completely different flows emanating from primary + secondary on the one hand and compact on the other, where all three view controllers just stick around during collapse and expand, is so simple and elegant. It took me only a very short time to make a working example that works on iPad toggling between splitscreen and fullscreen, and on iPhone 8 Plus rotating between portrait and landscape. Gone is all the kerfuffle with the obscure delegate methods and the button management; everything just works.

Cool, thanks!

The way to see all environment variable values is to add a run script to your build phases.

Bump. I repeat the question. Xcode 13 is final. I need the Vary For Traits feature. Some of my apps use it. Where is it?

The rule you are breaking is that capitalization matters when you spell a name. You're saying xFile = ... So the Swift compiler looks for the term xFile declared as a variable name in scope, to which something can be assigned. But the word xFile doesn't appear as a variable name in scope — just as the compiler is telling you. What does appear as a variable name in scope is xfile, which as far as Swift is concerned is a totally different name.

This isn't really a very useful solution. This change may bring down compile times but compile times are still atrociously slow. You change one line of one final class and it takes Xcode over a minute to recompile. That's criminal.

It's not actually hanging, it just takes a really long time. Keep your eye on the Finder status bar to see your hard drive slowly filling.

The answer from atbf is what helped me. You have to change the project setting build location and you have to close and reopen the project.

Me too, just started today. Feels like something belonging to Apple has suddenly started expiring.

Fixed. See https://stackoverflow.com/a/78421026/341994