IDE doesn't recognize Kotlin defined classes from Java

Cursor 0.48.8 on MacOS 15.4

This project demonstrates the problem. The readme explains. Clone the project, open it in Cursor, open JavaMain.java. In the Problems tab you will see The import com.example.Calculator cannot be resolved, see

. This is unexpeceted as the Java and Kotlin compiles and runs just fine in the terminal. Steps for doing that are in the README.