When a reactor build contains an interproject dependency, and the dependency project's build switches the project's POM file, the dependent project may get the wrong classpath for the dependency project as long as it references ${basedir}/target/classes. For example, the shade plugin produces a dependency-reduced POM, and sets it on the project instance using project.setFile(..). This act reorients the project's basedir according to the new POM, which can return the wrong location for the build.outputDirectory (since this is now based on build.directory, which is now based on basedir).