androidTestCompile fails to build aar

I have a project with multiple modules. Part of the project is broken into test modules I do not want included with the core code (as they are only used for testing). Since the latest update of Studio 2.2 and gradle 3.1, my androidTestCompile statements in my main app have begun failing with:

A problem was found with the configuration of task ':app:prepareXXXXTestAppLibraryUnspecifiedLibrary'. File '/Users/normandl/git/XXXX/Android/TestAppLibrary/build/outputs/aar/TestAppLibrary-release.aar' specified for property 'bundle' does not exist.

Of course if I change the directive in the app build.gradle file to compile project(":TestAppLibrary") from androidTestCompile(":TestAppLibrary) build is fine. So I have narrowed this down to the androidTestCompile directive.

I have also tried from the command line, and it fails their too, so it is not limited to studio, making me suspect the upgrade to gradle. I have tried this on 2.14.1 as well. everything was fine in gradle 2.13.1.

My back door option is to build a local aar, drop this directive so it does not build the library in the main app, only reference it. Less than ideal since it causes overhead in maintenance.