App Crashes Only On Testflight Build

ios, objective-c, swift, xcode

Solution

I solved the issue by changing the swift compiler optimization from `fastest` to `none`. I'm not sure if this is an ideal long term solution, but the build no longer crashes.

Problem

I have created an app on swift and tested it extensively using iPhone 6, iPhone 6 plus and iPhone 5 devices and all the simulators offered in Xcode. The app runs fine and does not crash when uploaded locally. (iOS 8) I finally submitted a build for Testflight. The app consistently crashes at the same place after downloading the app through the Testflight build. Is there a known issue where uploaded builds run differently than locally created builds? And how can I debug the issue with the Testflight build?

Original source