kelvingrove's puppet agent is stuck

root@kelvingrove:~# puppet agent --test
Info: Using configured environment 'production'
Info: Retrieving pluginfacts
Info: Retrieving plugin
Info: Retrieving locales
Info: Loading facts
Error: Failed to apply catalog: Parameter command failed on Exec[update-java-alternatives]: Command must be a String, got value of class Array (file: /etc/puppet/code/environments/production/modules/java/manifests/config.pp, line: 9)