alias property flip-flop for concat files

[ak0ska]

Hello,

We recently experienced a drop in the catalog duplication rate on our PuppetDB. Thanks to the very useful new debug feature, we believe it is due to a phenomena where the alias property of File resources created by the concat module oscillates as follows:

<       "alias" : "concat_/etc/krb5.conf",
---
>       "alias" : [ "concat_/etc/krb5.conf" ],

and

<       "alias" : [ "concat_/etc/krb5.conf" ],
---
>       "alias" : "concat_/etc/krb5.conf",

So sometimes it is an array of 1 string, and sometimes just a simple string. All other File resources (not created by concat) have the alias property as an array.

We use Puppet 3.4.3, PuppetDB 1.6.0 and concat module 1.1.0-rc1. We use several masters, each accessing the Puppet config over an NFS share, so there is no difference in the modules and manifests. All masters have Ruby 1.8.7 and same version of gems. When the catalog is manually compiled across all master using mco shell, the resulting alias is  always ' "alias" : "concat_/etc/krb5.conf" '.

The alias is defined here: https://github.com/puppetlabs/puppetlabs-concat/blob/1.1.0-rc1/manifests/init.pp#L174
The same is happening to the concat fragments.

Any ideas why and how this can happen?

Cheers,
ak0ska