When I try to run arkit scanner in xcode 10 I get an error in the Utilities.swift file saying ARReferenceObject has no member merging.
The merging(_:) API, which is used to merging the ARReferenceObject with other ARReferenceObjects,it is a iOS12+ Beta(early releases of Xcode10 beta doesn't contain this API yet), please upgrade your Xcode to Version 10.0 beta 5 (10L221o), I have tested it the demo scan app and it can build and run.