maven-antrun-plugin must be unique but found duplicate declaration of plugin org.apache.maven.plugins:maven-antrun-plugin

[MarkEWaite]

Jenkins and plugins versions report

Environment with plugin POM 5.13

Java 21.0.7 on AMD64 building from the master branch with Apache Maven 3.9.9 reports an unexpected warning.

[WARNING]
[WARNING] Some problems were encountered while building the effective model for org.jenkins-ci.plugins:preSCMbuildstep:hpi:999999-SNAPSHOT
[WARNING] 'build.plugins.plugin.(groupId:artifactId)' must be unique but found duplicate declaration of plugin org.apache.maven.plugins:maven-antrun-plugin @ org.jenkins-ci.plugins:plugin:5.13, /home/mwaite/.m2/repository/org/jenkins-ci/plugins/plugin/5.13/plugin-5.13.pom, line 787, column 15
[WARNING]
[WARNING] It is highly recommended to fix these problems because they threaten the stability of your build.
[WARNING]
[WARNING] For this reason, future Maven versions might no longer support building such malformed projects.
[WARNING]

What Operating System are you using (both controller, and any agents involved in the problem)?

Red Hat Enterprise Linux 8.10

Reproduction steps

1. Checkout a plugin that is using the 5.13 plugin POM
2. Compile the plugin with Java 21
3. Confirm that the unexpected warning message is displayed

Expected Results

No warning message should be displayed for duplicate declarations in the plugin POM file.

Actual Results

Warning message is displayed unexpectedly

Anything else?

No response

Are you interested in contributing a fix?

No

[MarkEWaite]

I think this was caused by:

• Prepare for JEP 451 #1130