[MASSEMBLY-970] Duplicate <include> in <dependencySet> causes "The following patterns were never triggered in this artifact inclusion filter" warning

**[Václav Haisman](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=wilx)** opened **[MASSEMBLY-970](https://issues.apache.org/jira/browse/MASSEMBLY-970?redirect=false)** and commented

```
[WARNING] The following patterns were never triggered in this artifact inclusion filter:
o 'org.python:jython-standalone'
```

The reason for the warning is a duplicate lines of `` in ``.

Here is a Git repository with the demonstration projects: [https://github.com/wilx/maven-assembly-includes-test-case-2](https://github.com/wilx/maven-assembly-includes-test-case-2).

Older versions did not show this warning. This warning in combination with `true` breaks build.

Maybe there should be a warning about duplicate `` instead that does not break the build with ``?

---

**Affects:** 3.4.2

Start with the demonstration projects in https://github.com/wilx/maven-assembly-includes-test-case-2 and reproduce the duplicate entries in a with true. Trace the artifact inclusion filter and its warning behavior; done means the duplicate include case no longer produces the reported build-breaking behavior and is covered by an appropriate test.

Written by the indexing model from the issue text.