Newbie maven issue building trunk

I am following the Building Pluto from Source instructions (http:// 
portals.apache.org/pluto/v11/getting-started.html) and encountering  
an issue in the "Building Pluto with Maven 2" step.

I have not previously used Maven. I've downloaded and installed Maven  
2.0.4 (http://maven.apache.org/download.html).

I've checked out pluto trunk to ~/src/pluto.

The install goal executes successfully from this directory.

But when attempting to execute the pluto:install goal (mvn  
pluto:install -DinstallDir=$CATALINA_HOME) I receive the following  
error:

[INFO] Searching repository for plugin with prefix: 'pluto'.
[INFO]  
------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO]  
------------------------------------------------------------------------
[INFO] The plugin 'org.apache.maven.plugins:maven-pluto-plugin' does  
not exist or no valid version could be found

Are there additional steps required in order build and install with  
Maven?

Thanks!

dircha