HockeyApp (via Landon Fuller and Andreas Linde):
It is currently not possible to support crash reports from builds using Bitcode. When uploading an app to the App Store and leaving the “Bitcode” checkbox enabled, Apple will use that Bitcode build and re-compile it on their end before distributing it to devices. This will result in the binary getting a new UUID and there is no way to download a corresponding dSYM.