$ mvn clean validate                                               
[INFO] Scanning for projects...
[WARNING] 
[WARNING] Some problems were encountered while building the effective model for org.wildfly.core:wildfly-core-testsuite-unstable-api-annotation-feature-pack:pom:25.0.0.Beta6-SNAPSHOT
[WARNING] 'build.plugins.plugin.(groupId:artifactId)' must be unique but found duplicate declaration of plugin org.apache.maven.plugins:maven-resources-plugin @ line 105, column 21
[WARNING] The expression ${artifactId} is deprecated. Please use ${project.artifactId} instead.
[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]