Exclusion patterns are ignored during a multi module reactor build

[jakub-bochenski]

In one project I have:

                <artifactId>maven-jar-plugin</artifactId>
                <executions>
                    <execution>
                        <id>default-test-jar</id>
                        <configuration>
                            <excludes>
                                <exclude>**/applicationContext.xml</exclude>
                            </excludes>
                        </configuration>
                    </execution>

Then when:

• I use the tests jar in another project,
• both projects are build in the same run (multi module build)
• the other project also has an applicationContext.xml file in it's test resources directory

I get the following reported:

  [WARNING] Found duplicate and different resources in [/home/jenkins/workspace/Acme_Job/acme/module/common_pod/build/testClasses, com.acme:common_platform:0.0.1-SNAPSHOT:jar:tests]:
  [WARNING] applicationContext.xml

Note: I did double-check that the tests-jar does NOT have the applicationContext.xml
When I build the projects separately, and not in the same reactor, the warning does NOT appear.

[hgschmie]

The duplicate-finder is not aware that you exclude this file from the jar build (and short of interpreting the exclusion rules of the jar build, it will not be possible to do so). So in the reactor build, it will look at the contents of src/test/resources and find the file and flag it as a duplicate.

This is a limitation because of the way the plugin works. The preferLocal option might solve this for you (it was introduced in 1.1.1), using <preferLocal>false</preferLocal> will force the plugin to use the built artifacts, not the contents of the local filesystem.