p2 director install fails because Central site includes an undefined reference to jboss.discovery.earlyaccess.site.url

22:35:15 run.director:
22:35:15      [echo] Profile Name: epp.package.jee
22:35:15      [echo] Install Path: /mnt/hudson_workspace/workspace/jbosstools-install-p2director.install-tests.matrix_4.3.mars/467eb389/eclipse
22:35:15      [echo] Source Sites: http://download.jboss.org/jbosstools/updates/nightly/core/4.3.mars/,http://download.jboss.org/jbosstools/discovery/nightly/core/4.3.mars//,https://dl-ssl.google.com/android/eclipse/,http://update.zeroturnaround.com/update-site-jboss/,${jboss.discovery.earlyaccess.site.url}
22:35:15      [echo] IUS to Install:
22:35:15      [echo] com.android.ide.eclipse.adt.feature.feature.group,com.android.ide.eclipse.ddms.feature.feature.group,com.android.ide.eclipse.gldebugger.feature.feature.group,com.android.ide.eclipse.hierarchyviewer.feature.feature.group,com.android.ide.eclipse.traceview.feature.feature.group,com.atlassian.connector.eclipse.feature.group,com.atlassian.connector.eclipse.jira.feature.group,com.atlassian.connector.eclipse.monitor.feature.group,com.collabnet.subversion.merge.feature.feature.group,com.github.sevntu.checkstyle.checks.feature.feature.group,edu.umd.cs.findbugs.plugin.eclipse.feature.group,net.java.dev.jna.feature.group,net.sf.eclipsecs.feature.group,net.sourceforge.pmd.eclipse.feature.group,org.eclipse.egit.feature.group,org.eclipse.egit.mylyn.feature.group,org.eclipse.jgit.feature.group,org.eclipse.jst.server_adapters.feature.feature.group,org.eclipse.jst.server_core.feature.feature.group,org.eclipse.jst.server_ui.feature.feature.group,org.eclipse.jst.server_userdoc.feature.feature.group,org.eclipse.m2e.feature.feature.group,org.eclipse.m2e.wtp.feature.feature.group,org.eclipse.m2e.wtp.jaxrs.feature.feature.group,org.eclipse.m2e.wtp.jpa.feature.feature.group,org.eclipse.m2e.wtp.jsf.feature.feature.group,org.eclipse.mylyn.bugzilla_feature.feature.group,org.eclipse.mylyn.commons.feature.group,org.eclipse.mylyn.context_feature.feature.group,org.eclipse.mylyn_feature.feature.group,org.eclipse.mylyn.git.feature.group,org.eclipse.mylyn.github.feature.feature.group,org.eclipse.mylyn.hudson.feature.group,org.eclipse.mylyn.ide_feature.feature.group,org.eclipse.mylyn.java_feature.feature.group,org.eclipse.mylyn.pde_feature.feature.group,org.eclipse.mylyn.team_feature.feature.group,org.eclipse.mylyn.versions.feature.group,org.jboss.ide.eclipse.as.feature.feature.group,org.jboss.tools.aerogear.thym.feature.feature.group,org.jboss.tools.arquillian.feature.feature.group,org.jboss.tools.common.mylyn.feature.feature.group,org.jboss.tools.feedhenry.feature.feature.group,org.jboss.tools.forge.feature.feature.group,org.jboss.tools.forge.m2e.feature.feature.group,org.jboss.tools.jst.angularjs.feature.feature.group,org.jboss.tools.jst.jsdt.feature.feature.group,org.jboss.tools.livereload.feature.feature.group,org.jboss.tools.m2e.wro4j.feature.feature.group,org.jboss.tools.maven.apt.feature.feature.group,org.jboss.tools.maven.cdi.feature.feature.group,org.jboss.tools.maven.feature.feature.group,org.jboss.tools.maven.hibernate.feature.feature.group,org.jboss.tools.maven.jbosspackaging.feature.feature.group,org.jboss.tools.maven.portlet.feature.feature.group,org.jboss.tools.maven.seam.feature.feature.group,org.jboss.tools.openshift.egit.integration.feature.feature.group,org.jboss.tools.openshift.express.feature.feature.group,org.jboss.tools.project.examples.seam.feature.feature.group,org.jboss.tools.runtime.seam.detector.feature.feature.group,org.jboss.tools.seam.feature.feature.group,org.jboss.tools.vpe.browsersim.feature.feature.group,org.jboss.tools.vpe.cordovasim.feature.feature.group,org.sonatype.m2e.egit.feature.feature.group,org.springframework.ide.eclipse.ajdt.feature.feature.group,org.springframework.ide.eclipse.aop.feature.feature.group,org.springframework.ide.eclipse.autowire.feature.feature.group,org.springframework.ide.eclipse.batch.feature.feature.group,org.springframework.ide.eclipse.data.feature.feature.group,org.springframework.ide.eclipse.feature.feature.group,org.springframework.ide.eclipse.integration.feature.feature.group,org.springframework.ide.eclipse.maven.feature.feature.group,org.springframework.ide.eclipse.mylyn.feature.feature.group,org.springframework.ide.eclipse.osgi.feature.feature.group,org.springframework.ide.eclipse.security.feature.feature.group,org.springframework.ide.eclipse.webflow.feature.feature.group,org.springsource.ide.eclipse.commons.feature.group,org.testng.eclipse.feature.group,org.tigris.subversion.clientadapter.feature.feature.group,org.tigris.subversion.clientadapter.svnkit.feature.feature.group,org.tigris.subversion.subclipse.feature.group,org.tigris.subversion.subclipse.graph.feature.feature.group,org.tigris.subversion.subclipse.mylyn.feature.group,org.tmatesoft.svnkit.feature.group,org.zeroturnaround.eclipse.feature.feature.group,org.zeroturnaround.eclipse.m2e.feature.feature.group,org.zeroturnaround.eclipse.wtp.feature.feature.group

22:35:33    [p2.dir] java.lang.IllegalArgumentException: Location must be absolute: $%7Bjboss.discovery.earlyaccess.site.url%7D