Drift detection causes failure when resource has the same envvar name multiple times

[DerRockWolf]

This is in general supported by Kubernetes, at least you can do something like this and Kubernetes accepts it:

spec:
  containers:
    - name: test
      env:
        - name: VAR
          value: FOO
        - name: VAR
          value: BAR

The VAR variable will then hold BAR.
I couldn't find something in the official Kubernetes docs that describes this behavior, but I've found this third-party article.

If a HelmRelease renders to such a resource and spec.driftDetection.mode is enabled the helm-controller will fail to reconcile the HelmRelease with this error:

  - lastTransitionTime: "2025-10-08T20:00:29Z"
    message: 'Could not determine release state: unable to determine cluster state:
      Deployment/minecraft/togather-minecraft dry-run failed: failed to create typed
      patch object (minecraft/togather-minecraft; apps/v1, Kind=Deployment): .spec.template.spec.containers[name="togather-minecraft-mc-backup"].env:
      duplicate entries for key [name="BACKUP_NAME"]'
    observedGeneration: 92
    reason: StateError
    status: "False"
    type: Ready