HELM_DIFF_IGNORE_UNKNOWN_FLAGS doesn't ignore --atomic

[frankwese]

Hi,
I am trying to use helm diff in a github workflow. Therefore I added a step to prepare all helm arguments and pass these to either helm diff upgrade or helm upgrade.
Despite that I set

        - name: Show diff
          shell: bash
          env:
              FORCE_COLOR: '1'
              HELM_DIFF_COLOR: true
              HELM_DIFF_IGNORE_UNKNOWN_FLAGS: true
              HELM_DIFF_OUTPUT_CONTEXT: 1
          run: >
              helm diff upgrade ${{steps.helm_args.outputs.OUT}}

helm-diff complains about unknown flag: --atomic
Do I do something wrong?

[yxxhero]

@frankwese please show some logs.

[frankwese]

frank.wesemann@w0gnr ipc-site % export HELM_DIFF_IGNORE_UNKNOWN_FLAGS=true                                                                                  
frank.wesemann@w0gnr ipc-site % helm diff upgrade diddel wiremock/ --install --namespace notexisting --atomic --debug
Error: unknown flag: --atomic
Usage:
  diff upgrade [flags] [RELEASE] [CHART]
…

[yxxhero]

see: #538