I found the following work around - tested and worked:
…
configurations {
scalaCompiler
}
configurations.scalaCompiler.transitive = false
…
dependencies {
…
scalaCompiler “org.scalamacros:paradise_2.11.7:2.1.0-M5”
…
}
…
def String scalaCompilerOptions="-Xplugin:$configurations.scalaCompiler.singleFile.path"
compileScala.scalaCompileOptions.additionalParameters = [scalaCompilerOptions]
compileTestScala.scalaCompileOptions.additionalParameters = [scalaCompilerOptions]
-cl