Purpose

Starting with version 6.6.0, Hibernate includes an annotation processor that creates files within a directory entity.index in the source output directory (https://hibernate.atlassian.net/browse/HHH-18162).

When used in combination with IntelliJ, this causes the following error:

java.lang.LayerInstantiationException: Package entity.index in both module com.github.martinleim.modulea and module com.github.martinleim.moduleb

How to reproduce

Tested on IntelliJ IDEA 2024.3.3 Ultimate Edition, Build #IU-243.24978.46

• Import into IntelliJ as Maven project
• Run "Build project". Notice how the target/classes directory does not contain the entity directory
• Open com.github.martinleim.moduleb.Main and execute the main method.
• Now, IntelliJ again builds the project. This time, the entity directory from target/generated-sources/annotations is included in target/classes
• After the build, the main method is run and produces the error above.