maven-dependency-plugin:unpack Error - maven-3

Question

I'm trying to extract some .exe files from a dependency jar file and put them under ${project.build.directory}/classes/.
But when I execute:
mvn clean compile dependency:unpack
I get:
Failed to execute goal org.apache.maven.plugins:maven-dependency-plugin:2.10:unpack (default-cli) on project simple: Either artifact or artifactItems is required -> [Help 1
I have verified that the dependencies are available in my local repository.
In my example pom below I've used junit as an example, but no matter which dependency I list, I get the same error.
pom.xml:
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.10</version>
<executions>
<execution>
<id>unpack</id>
<phase>package</phase>
<goals>
<goal>unpack</goal>
</goals>
<configuration>
<artifactItems>
<artifactItem>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.10</version>
<type>jar</type>
<overWrite>false</overWrite>
<outputDirectory>${project.build.directory}/classes/externaltools</outputDirectory>
<includes>**/*.txt</includes>
</artifactItem>
</artifactItems>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</pluginManagement>
</build>

Answer 1

The issue is due to you cannot use mvn clean compile dependency:unpack and <executions> tags together.
In documentation Maven Depdendency Plugin at the bottom part of the page you can read:
If you intend to configure this mojo for execution on the command line using: mvn dependency:unpack you must not put the configuration inside the executions tag. Your configuration should look like this:
<project>
[...]
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.10</version>
<configuration>
<artifactItems>
<artifactItem>
<groupId>[ groupId ]</groupId>
<artifactId>[ artifactId ]</artifactId>
<version>[ version ]</version>
<type>[ packaging ]</type>
<classifier> [classifier - optional] </classifier>
<overWrite>[ true or false ]</overWrite>
<outputDirectory>[ output directory ]</outputDirectory>
<destFileName>[ filename ]</destFileName>
<includes>[ comma separated list of file filters ]</includes>
<excludes>[ comma separated list of file filters ]</excludes>
</artifactItem>
</artifactItems>
<!-- other configurations here -->
</configuration>
</plugin>
</plugins>
</build>
[...]
</project>
I have tried removing the <execution> tags and works perfectly!