Entity meta-model classes not generated when compiling EJB module via POM project

I have a Maven project structure like this:

main (POM project)
|-ejb (POM project)
| |-data1 (EJB module)
| |-data2 (EJB module)
| |-ejb-jsf-converters (Java application)
|-web (POM project)
| |-... (A bunch of Web applications)
|-ear (POM project)
  |-web1-ear (Java EE7 EAR project)
  |-web2-ear (Java EE7 EAR project)

I can compile everything in the order data1, data2, ejb-jsf-converters, web and finally ear. After that I can deploy web1-ear and web2-ear and all works fine. But having to compile everything in a specific order is annoying. I want to be able to just compile main.

But I can't.

The problem is that I have a lot of entities in data1. And these entities of course have a lot of meta-model classes. To generate them, I have these 2 snippets in data1's pom.xml:

...
<dependency>
    <groupId>org.eclipse.persistence</groupId>
    <artifactId>eclipselink</artifactId>
    <version>2.4.2</version>
    <scope>provided</scope>
</dependency>
<dependency>
    <groupId>org.eclipse.persistence</groupId>
    <artifactId>javax.persistence</artifactId>
    <version>2.0.5</version>
    <scope>provided</scope>
</dependency>
...
<plugin>
    <groupId>org.bsc.maven</groupId>
    <artifactId>maven-processor-plugin</artifactId>
    <version>2.2.4</version>
    <executions>
        <execution>
            <id>process</id>
            <goals>
                <goal>process</goal>
            </goals>
            <phase>generate-sources</phase>
            <configuration>
                <compilerArguments>-Aeclipselink.persistencexml=src/main/resources/META-INF/persistence.xml</compilerArguments>
                <processors>
                    <processor>org.eclipse.persistence.internal.jpa.modelgen.CanonicalModelProcessor</processor>
                </processors>
            </configuration>
        </execution>
    </executions>
</plugin>
...

When I compile main instead of data1, all of the sudden, persistence.xml cannot be found and no meta-model classes are generated or found. I can change

<compilerArguments>-Aeclipselink.persistencexml=src/main/resources/META-INF/persistence.xml</compilerArguments>

to

<compilerArguments>-Aeclipselink.persistencexml=ejb/data1/src/main/resources/META-INF/persistence.xml</compilerArguments>

and then I can compile the main project. But when I do that, I no longer can compile data1. Then it's data1 that cannot find persistence.xml and generate meta-model classes. Being able to compile main is great, but being forced to compile main each time I just want to compile data1 is a pain. Compiling main takes 10-15 times longer than compiling data1.

I know I can make it work by specifying the absolute path, instead of a relative path, but many different machines need to compile this. The absolute path will not be the same on all of them.

I thought about using an environment variable, but I'm not sure it will work very well in all cases. For example when the project is compiled by a Jenkins slave.

How can I make this work, so I can compile both main and data1 as I see fit?