Rudder

With Rudder 4.2.7~rc1~git201806070147-stretch0, and rudder dsc plugin 4.2-1.8.0, I get the following error at generation

⇨ Policy update error for process '6' at 2018-06-08 10:48:15
⇨ Cannot write configuration node
⇨ Boxed Error

Logs aren't very informative:

[2018-06-08 10:48:15] INFO  com.normation.rudder.services.policies.nodeconfig.NodeConfigurationServiceImpl - Configuration of following nodes were updated, their promises are going to be written: [be75889c-8577-4e61-9e44-e377421f6013, 3ba29b92-0355-482e-ad16-dc580cce1079, root]
[2018-06-08 10:48:15] DEBUG com.normation.rudder.services.policies.write.Cf3PromisesFileWriterServiceImpl - 86 promises templates read in 218 ms
[2018-06-08 10:48:15] DEBUG policy.generation - Paths computed and templates read in 219 ms
[2018-06-08 10:48:15] DEBUG com.normation.rudder.services.policies.write.PrepareTemplateVariablesImpl - Writting promises for node 'server.rudder.local' (root)
[2018-06-08 10:48:15] DEBUG com.normation.rudder.services.policies.write.BuildBundleSequence - Sorted Technique (and their Rules and Directives used to sort): [Distribute the policy to servers: [distributePolicy | Distribute Policy]][Users: [Global configuration for all nodes | Users]][Common policies: [Rudder system policy: basic setup (common) | Common]][Make an inventory of the node: [Rudder system policy: daily inventory | Inventory]][Server roles: [Rudder system policy: Server roles | Server Roles]]
[2018-06-08 10:48:15] DEBUG com.normation.rudder.services.policies.write.PrepareTemplateVariablesImpl - Writting promises for node 'agent2.rudder.local' (3ba29b92-0355-482e-ad16-dc580cce1079)
[2018-06-08 10:48:15] DEBUG com.normation.rudder.services.policies.write.BuildBundleSequence - Sorted Technique (and their Rules and Directives used to sort): [Users: [Global configuration for all nodes | Users]][Common policies: [Rudder system policy: basic setup (common) | Common]][Make an inventory of the node: [Rudder system policy: daily inventory | Inventory]]
[2018-06-08 10:48:15] DEBUG com.normation.rudder.services.policies.write.PrepareTemplateVariablesImpl - Writting promises for node 'agent1' (be75889c-8577-4e61-9e44-e377421f6013)
[2018-06-08 10:48:15] DEBUG com.normation.rudder.services.policies.write.BuildBundleSequence - Sorted Technique (and their Rules and Directives used to sort): [Users: [Global configuration for all nodes | Users]][DSC Common policies: [Rudder system policy: base configuration for DSC based agent | DSC Based agent configuration]]
[2018-06-08 10:48:15] DEBUG com.normation.rudder.services.policies.PromiseGenerationServiceImpl - Policy generation completed in 466 ms
[2018-06-08 10:48:15] ERROR com.normation.rudder.batch.AsyncDeploymentAgent$DeployerAgent - Error when updating policy, reason Cannot write configuration node <- Boxed Error
[2018-06-08 10:48:15] DEBUG com.normation.rudder.batch.AsyncDeploymentAgent - Flag file '/opt/rudder/etc/policy-update-running' successfully removed