I downloaded Xcode 6 GM and submitted two Swift apps to the app store today. Both passed all pre-upload verification and all the other stuff they had to pass and were succe
For me everything was very simple. I had the same problem and didn't know what to do for a week.
After you submit an archived application, you will see certificate for distribution in small popup window. There is a checkbox after it, which you should uncheck. After that you will submit it and get an email about symbol files. BUT it isn't problem. It's just a warning; not an error! If you uncheck that checkbox, your app will be sent correctly. I hope it may help you.
Screenshot of the checkbox and the popup: