Build and run the capture session based scanner sample. Start scanning but do not tap Done. Click the iPad home button causing the app to resign the active state. EXC_BAD_ACCESS is thrown.
NOTE: This was tested using wireless debugging in Xcode
My workaround is to disable capture session streaming when the app resigns active. Apparently some number of motion callbacks continue to be received after streaming is disabled, and exceptions are thrown in processDeviceMotion. That problem was mitigated by adding a flag to the device motion updates after streaming is disabled. Not a pretty solution, but seems to work.