As was brought up by Craig Doremus, the new Pluto 2.0 groupId, org.apache.portals.pluto, can cause a lookup problem of the maven pluto plugin if both the old groupId, org.apache.pluto, and the new groupId
are used/needed as maven settings.xml <pluginGroup> definition because they currently use the same plugin prefix, pluto.
Solution is simple: change the plugin prefix for Pluto 2.0 to pluto2.
As result, the Pluto 2.0 plugin then needs to be invoked using:
$mvn pluto2:install -DinstallDir=<your appserver location>