The distribution module of Openfire’s Maven project generates the basic Openfire distributions. It does so by using the Maven assembly plugin, and optionally the install4j plugin.

The Maven module declares its packaging type to be jar. This indicates that the Maven build is to generate a Jar file. This is not the case: the only artifacts to be produced are the Maven assembly and install4j ones. As the module has no relevant resources, an empty jar file is produced. The build warns about this:

The Jar file that’s produces is pointless. It should not be produced at all. One way of achieving this is to change the packaging type of the module from jar to pom. Note that this does introduce changes in the default lifecycle bindings. To my understanding, it will no longer have goals bound to them that this module does not / should not use anyways (like compiler:compile and surefire:test.