<project>
 ...
 <build>
  <plugins>
   <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-shade-plugin</artifactId>
    <version>3.0.0</version>
    <executions>
     <execution>
      <phase>package</phase>
      <goals>
       <goal>shade</goal>
      </goals>
      <configuration>
       <transformers>
        <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
         <mainClass>org.sonatype.haven.HavenCli</mainClass>
        </transformer>
       </transformers>
      </configuration>
     </execution>
    </executions>
   </plugin>
  </plugins>
 </build>
 ...
</project>