Xcode debugger does NOT allow Crashlytics to process crash reports. Yeah, that seem weird even to me when I read that first time but it is a fact (Source). That’s is the reason we never see crash report When:
– running app in Simulator
– running app on iDevice by directly build and run from Xcode with debugger on.
To make sure a crash is reported during your testing (copied from Crashlytics support site):
1. Launch simulator
2. Press stop
3. Launch your app and force a crash
4. Relaunch the app from simulator
5. See the crash report in the web dashboard.
Added a reference; Crashlytics also provides a short article on a quick way to force a crash.