...
<properties>
<izpack.version>5.0.0-beta9</izpack.version>
<izpack.staging>${project.build.directory}/staging</izpack.staging>
</properties>
...
${project.build.directory}typically references the compilation ./target/ directory of your module- Properties from your Maven project compiling the IzPack project can be directly references in the install.xml using the property name enclosed in '@{' and '}' , for example:
<jar src="@{appizpack.stage.dirstaging}/lib/appcore.jar"/>This applies just on properties defined in the calling project, not for properties seen in the calling project.
...