Connection to daemon was invalidated
My app is using Firebase Analytics and I believe starting in iOS 13.2 started getting the errors described here: Why I get the console warning: [Process] kill() returned unexpected error 1 when I load a WKWebView in iOS13.2?
I guess it wasn't a big deal
Since I planned for my app to go live in January, I began bigger tests in physical devices. I noticed after a while the app started to behave erratically, specially after receiving a [general] Connection to daemon was invalidated error. This doesn't occur in the simulator
Searching the internet I found a post that describes the same problem: https://forums.developer.apple.com/thread/124306
In my case, only Firebase seems to be calling WKWebView, but every time I open the UIMenuController I get the error described in the console and the app appears to be missing inputs. This is specially troublesome with UIScrollViews, which my app uses a lot. The pinch gesture seems to work at will. On an iPhone 6s, the issue isn't as noticeable, on an iPad, it's like a 50% chance the pinch gesture will work properly
Outside of removing Firebase, is there a way to mitigate this issue?
1 June 2020: The console message still persists, however, I have seemed to resolve the UIScrollView issue by deactivating delaysContentTouches, now the pinch gesture seems to work most of the time
23 October 2020 If anyone notices their app starting to behave erratically with no apparent reason I HIGHLY suggest to test it on an iOS 13 physical device if possible. Seems that Apple removed the warning from iOS 14, but testing it on iOS 13 you can pin point the exact reason after the warning appears in the console
Answer
Upon further testing, I've reduced the view down to a dead-simple UI view with a single SwiftUI TextField and the 'Connection to daemon was invalidated' still appears after I type the first character into the field. Soon thereafter the app crashes with a sigAbort. (So I don't think the reason is the UITextView wrapper I was using in the previous post). Once the invalidated message appears the app is doomed to crash, not right away but soon thereafter.
I have no idea what causes the 'invalidate' message and a Google search seems to imply that no-one else does either. Some folks appear to have made (experimental?) changes to their UI that stops the message but it appears to be impossible to determine a definite cause. (and like before it only occurs on a real phone)