I analyzed again the alignViewportToDocumentEndLocationIfNeeded() you provided, and noticed that despite it being called from textViewportLayoutControllerDidLayout the viewportLayoutController.viewportRange! is sometimes nil (and crashes). I also noticed that the adjustement sometimes failing to adjust viewport to display the end of the document - all of that happens when scrolling is done fast - I'm aware it is vague, but I don't have more context to it myself, it looks misterious to me

I don't see any way to achieve that, unless you ensure the layout of the whole document that is also my experience. However, the NSTextView/UITextView somehow maintain stable scrollbar position while scrolling (moving the viewport). We struggle to understand how to archive the same with TextKit2 API. Any advice?

FYI the code you proposed is very slow and unusable in production setup. I wish we had a better way to calculate usageBoundsForTextContainer in a performanet and realiable (or usable really) way

The Xcode 16.3 can't build my project due to mysterious crashes, so this is impossible in the near future.

for macOS 15.4 RC2, this is FB number: FB17035420

I was not able to reproduce the issue with macOS 15 beta 7. It remains broken on macOS 14 (and 14 only)

Layout information on textViewportLayoutController is up-to-date at the point of this call either documentation of the textViewportLayoutControllerDidLayout is not accurate or there is a bug. I observed the same behavior.

There is another call textLayoutManager.ensureLayout(for: NSTextRange(location: textLayoutManager.documentRange.endLocation)) that sounds like it should perform the layout for the whole document - but it's not. On that note usageBoundsForTextContainer is KVO observerable, but the updates are not published at all, that (FB13291926)

usageBoundsForTextContainer value changes, but the KVO notification does't work at all. I reported it FB13291926 last year.

NSTextContentStorage provides textStorage property. NSTextContentStorage is already specialized implementation that uses NSTextStorage as its storage. how can I link multiple NSTextContentStorage to the same NSTextStorage? you don't.

I have the same issue (Xcode 15 beta 7). It's annoying to the extend that even though USB cable is connected, but WiFi is disabled, it won't even connect.

It's been 5 years, and looks like things changed. As of today /Applications/Xcode.app/Contents/Developer/usr/bin/simctl is just a trampoline to execute /Library/Developer/PrivateFrameworks/CoreSimulator.framework/Versions/A/Resources/bin/simctl that to my surprise does not need security scoped bookmark to launch. Sandboxed app runs simctl "just like that". That something I didn't expect.