The Fast App Resume plus tombstoning bug that made my head hurt

I'm sharing this in the hope that awareness of this issue will help save someone else some time and confusion

I've discovered odd behaviour with Fast App Resume when the debug option “Tombstone upon deactivation while debugging” is enabled.

When triggering a resume via a deep link when the app was originally launched via that same deep link, a Back navigation is triggered rather than a Reset navigation.

This matters because if you have logic that is based on the navigation method and expectations about the back stack (as you are very likely to have if your resume behaviour does anything other than mimic the replace behaviour) this scenario is likely to break your logic.

This has been confirmed as a known bug that has apparently been fixed in a future version of the tools.

You have been warned. Test Fast-App-Resume and tombstoning behaviour very carefully.