<Java 9 module cannot access files in same module>...

# stackoverflow

[user]

Java 9 module cannot access files in same module
The whole project can be viewed here.
I have the following minimal demo project:
package com.example.demo

import io.swagger.annotations.Api

@Api(tags = [API_NAME])
class DemoClass

const val API_NAME = "demo"

fun main() = println("Hello World!")

Works perfectly fine as is. However now I want to add the Java 9 module system. I add a module-info.java under src/main/kotlin with this content:
module com.example.demo...