Xcode 16.3 does fix this debugger crash. But it caused a whole slew of new crashes in our app. Mostly of these crashes end with: _dispatch_assert_queue_fail We do have a mixed swift concurrency/dispatch queue codebase which could be related. The most common cause I have found is posting to notification centre from a background thread. I am not able to reproduce this issue in an empty project though.

my solution was to wrap a UITextView in UIViewRepresentable. You can implement the new sizeThatFits API in UIViewRepresentable to ensure that the view sizes itself to fit its UIView content. Edit: Also using a TextField with a vertical growing axis seems to work as well. But the return button seems to submit the text field rather than adding new lines like one would expect.

In a brand new project it works fine. Which is why I suspect something is wrong with our build config. I am just not sure where to begin because the app does not even reach the app delegate.

I figured it out, solution below

having the same issue as saibot CocoaMQTT is basically abandoned at this point. I am planning on switching to MQTT-NIO