The weird iOS8 + Unity3D hiccup

Question

We've run into a strange problem when using Unity3D and iOS8. After about 1 minute there is a large (sometime a bit smaller) hiccup and we can't figure out why. Garbage collection?

We spent a few days trying to find out what the problem was and then created a minimalistic demo project where the exact same problem occurs.

The hiccup does not appear on iOS 7 or lower devices, not on Android and not in the editor. Only iOS8. We've tried build both with the latest release of Unity and the latest 4.6 beta.

Does anyone have a suggestion on how to fix this? Is it a bug in Unity3D?

Demo project:

• Click the "Black bar" in the first scene to get to scene two where the problem occurs.
• Look closely at the casinos. After about 1 minute you will see that they stop for a moment and then jump forward. As if a few frames were missed.
• The problem does not seem to appear if we go straight to "scenetwo" from launch.

https://github.com/dale/demoproject-hiccup

EDIT 2014-10-20:

Unity has now responded with this. "We got other reports on this issue. It seems to be caused by new "feature" of iOS8, where is watchdog is generating exception report if your app is shuffling threads too often. We are looking into ways how to mitigate/avoid these reports."

Answer 1

Unity has now responded with this.

"We got other reports on this issue. It seems to be caused by new "feature" of iOS8, where is watchdog is generating exception report if your app is shuffling threads too often. We are looking into ways how to mitigate/avoid these reports."