[MJAVADOC-790] The code being documented uses modules but the packages defined in X are in the unnamed module

**[Gili](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=cowwoc)** opened **[MJAVADOC-790](https://issues.apache.org/jira/browse/MJAVADOC-790?redirect=false)** and commented

I thought that https://issues.apache.org/jira/browse/MJAVADOC-555 fixed this problem, but I have just run into it again.

Given:

```java

org.apache.maven.plugins
maven-javadoc-plugin


attach-javadocs

jar


public
Requirements Jackson Plugin ${project.version} API
Requirements Jackson Plugin ${project.version} API


--override-methods
summary


https://www.javadoc.io/doc/com.fasterxml.jackson.core/jackson-databind/2.17.0/




https://cowwoc.github.io/requirements.java/${project.version}/docs/api/
${project.basedir}/../java/target/apidocs



com.github.cowwoc.requirements.jackson.internal,
com.github.cowwoc.requirements.jackson.internal.*

```

I get this warning:

```java
[INFO] --- javadoc:3.6.3:jar (attach-javadocs) @ jackson ---
[INFO] No previous run data found, generating javadoc.
[WARNING] Javadoc Warnings
[WARNING] warning: The code being documented uses modules but the packages defined in https://www.javadoc.io/doc/com.fasterxml.jackson.core/jackson-databind/2.17.0/ are in the unnamed module.
[WARNING] 1 warning
```

Any idea why this is happening to Jackson's Javadoc but not to other non-modules like Guava?

---

**Affects:** 3.6.3

Reproduce the warning with the maven-javadoc-plugin 3.6.3 jar execution and the configuration shown, using the Jackson Javadoc link and offline link. Compare this case with the Guava case and trace the plugin's module/package handling; done means the cause is identified and a verified fix or regression test covers the warning.

Written by the indexing model from the issue text.