Just installed Xcode 11.0 beta (11M336w), and once running an empty app getting this console error:
[general] CFLocaleCopyCurrent() failed to look up current locale via 'AppleLocale' and 'AppleLanguages' in user preferences; falling back to locale identifier 'en_US' as the default. Consider checking Console for sandbox violations from this process for reading from preferences, or enabling CoreFoundation debug logging for more information. This will only be logged once.
I'm pretty sure it's irrelevant, but worth mentioning that the empty app uses SwiftUI