"Unresolved reference" when trying to use a layout from a library module


Hi, I have the following setup:

Kotlin 1.1.51
Android Studio 3.0
Android Gradle plugin 3.0
Gradle 4.1
androidExtensions { experimental = true }

I get the following Gradle build errors:

Error:(5, 39) Unresolved reference: item
Error:(16, 9) Unresolved reference: btn

I made a repro project https://github.com/sevar83/kotlinx-unresolved-res
from a blank template in AS. I just added a library module with kotlinX experimental and one layout. Then I try to use this layout in the app module. Note that I’ve tried with both api project(':lib') and implementation project(':lib') but no difference.