archunit included in runtime classpath via spring-modulith-core even when not using spring-modulith-runtime

[JBraddockm]

I'm encountering an unexpected issue where com.tngtech.archunit:archunit is included in my runtime classpath, even though I'm not using spring-modulith-runtime and I only depend on spring-modulith-starter-core.

Problem

I'm building a JavaFX application with Spring Boot and Spring Modulith. My build.gradle.kts includes:

implementation("org.springframework.modulith:spring-modulith-starter-core") 
implementation("org.springframework.modulith:spring-modulith-starter-jdbc")
// This is a local repo, patched to work with SQLite with Spring Data JDBC.
implementation("org.springframework.modulith:spring-modulith-events-jdbc:1.4.2-SNAPSHOT") 
testImplementation("org.springframework.modulith:spring-modulith-starter-test")
testImplementation("org.springframework.modulith:spring-modulith-docs")

However, ArchUnit ends up in the compiled application's classpath, which bloats the final artifact and is unused at runtime. I am using jpackage to bundle the app image, which adds the ArchUnit jar to the custom runtime it generates.

Investigation

Running

./gradlew dependencyInsight --dependency archunit --configuration runtimeClasspath

Yields

com.tngtech.archunit:archunit:1.4.1
\--- org.springframework.modulith:spring-modulith-core:1.4.1
     \--- org.springframework.modulith:spring-modulith-starter-core:1.4.1
          +--- runtimeClasspath (requested org.springframework.modulith:spring-modulith-starter-core)                                                                                                                                 
          \--- org.springframework.modulith:spring-modulith-starter-jdbc:1.4.1
               \--- runtimeClasspath (requested org.springframework.modulith:spring-modulith-starter-jdbc)  

This shows that spring-modulith-core, and spring-modulith-starter-jdbc includes ArchUnit directly in compile/runtime scope, even though ArchUnit is meant for architectural tests only.

Workaround

I'm currently excluding ArchUnit manually in my Gradle config from spring-modulith-starter-core and spring-modulith-starter-jdbc.

Apologies if this is actually an expected behaviour.

Thanks.