Maven shade plugin build fails without 'clean' goal

[SylvainJuge]

Describe the bug

Build with the package goal fail if there is no clean goal executed.

It seems that maven-shade-plugin is not able to properly handle a resource file, thus the root cause is likely in the maven-shade-plugin project.

Error creating shaded jar: duplicate entry: META-INF/services/co.elastic.apm.agent.shaded.stagemonitor.configuration.ConfigurationOptionProvider

How to reproduce

• execute first build: mvn clean package -DskipTests -Dmaven.javadoc.skip=true
• try to execute another build without clean will fail mvn package -DskipTests -Dmaven.javadoc.skip=true

Workaround

Always execute the clean goal makes it work, but means doing extra work as the project is re-built from scratch.

[tisonkun]

Here apache/maven-shade-plugin#150 is the fix for upstream. I've verified locally. If you're still interested in this issue, please react an emoji to prioritize it :)