[Puppet Users] Problem with Hiera deep merge

Hi Puppet users,

I've been using Hiera's deep merge feature on class parameters for months,
however when I try to pair it with the create_resources function things get
ugly.

Situation:
I want to deploy a set of Unix users on all my machines. They have standard
rights by default and get access to the wheel group on a per-server basis
depending on their needs.

In my module I have:

manifests/user.pp
And in Hiera:

hiera/common.yaml

*It works great so far.* All my users are deployed on all machines.

Now I try to add the user foo to the wheel group on dev_server:

hiera/dev_server.example.com.yaml
Since the deeper
<http://docs.puppetlabs.com/hiera/1/lookup_types.html#deep-merging-in-hiera--120>
merge bahavior is enabled this should merge my user list just fine.
But... BANG! It all breaks apart:
However, if I query Hiera from the shell, it returns the expected user hash:

$ hiera --hash user_list ::clientcert=dev_server.example.com

Corruption? Madness? Did I miss something crucial when reading through the
documentation?

Thank you in advance for the hints :)

*Toni*

-----------------------------------------------------------------------------------------------

Just for your information:

    - Puppet 3.6.2
    - Hiera 1.3.4
    - deep_merge gem 1.0.1

Here is my hiera.yaml file (Puppet and the command line tool use strictly
the same file)

hiera.yaml