In a new directory, execute the following command to generate a default webapp:

mvn archetype:generate -DgroupId=com.xyz -DartifactId=wheres-my-manifest-file -DarchetypeArtifactId=maven-archetype-webapp -DarchetypeVersion=1.5 -DinteractiveMode=false

Open the pom.xml and add the configuration section below, save:

<plugin>
  <artifactId>maven-war-plugin</artifactId>
  <version>3.4.0</version>
    <configuration>
        <archive>
            <manifestEntries>
              <Project-Name>wheres-my-manifest-file</Project-Name>
              <Build-Number>1.0</Build-Number>
            </manifestEntries>
        </archive>
    </configuration>
</plugin>

In a shell, in the directory above, containing your pom.xml, execute mvn package. The target folder is created. Look in /target/wheres-my-manifest-file/META-INF. There is no manifest.mf file.

I've tried many things to get this file to generate, with no luck. Does anyone know how to get Maven to create this file? It has no problem creating the META-INF folder.