Graphite issues on the Learning VM need help please

I have started going through the Learning VM and run into an issue on the "Power of Puppet" module. I have followed the guide to the letter and increased VM ram to 4GB at the start. I get through the first section and install graphite using the puppet command:

puppet module install dwerder-graphite

And this works fine. I create the class and change the parameters as it says:

Set the parameters, as follows:

    gr_web_server = none
    gr_django_pkg = django
    gr_django_provider = pip
    gr_django_ver = "1.5"

But the next part tells me to install graphite using puppet:

puppet agent --test

This is where it fails and I get the following errors:

root@learning:~ # puppet agent --test
Info: Using configured environment 'production'
Info: Retrieving pluginfacts
Info: Retrieving plugin
Info: Loading facts
Error: Could not retrieve catalog from remote server: Error 400 on SERVER: Evaluation Error: Error while evaluating a Resource Statement, Evaluation Error: Error while evaluating a Function Call, having $gr_web_server => 'wsgionly' requires use of $gr_web_user and $gr_web_group at /etc/puppetlabs/code/environments/production/modules/graphite/manifests/config.pp:65:9 on node learning.puppetlabs.vm
Warning: Not using cache on failed catalog
Error: Could not retrieve catalog; skipping run

Now if i remove the changes i made then run:

puppet agent -t

Then it runs through that process fine however with the changes in it fails. Any help is really appreciated as I would like to continue with this Learning VM. Kris