See https://github.com/openshift/oc-mirror/issues/1037 for more context.

Description of problem

I'm trying to mirror this Helm Chart (openshift-helm-charts/charts@main/charts/redhat/redhat/redhat-developer-hub/1.4.1/redhat-developer-hub-1.4.1.tgz), but for some reason, oc-mirror is not able to detect the images to mirror.
I narrowed it down to the way the Chart is being rendered. This Helm Chart is using a sub-chart as an aliased dependency, and this is causing the errors: https://github.com/redhat-developer/rhdh-chart/blob/1.4.1/charts/backstage/Chart.yaml#L26-L29

How reproducible
Always. Was initially tested with oc-mirror v1, but ran into the same issue with oc-mirror v2

Steps to Reproduce

Just trying to mirror the RHDH Helm Chart with the following ImageSetConfig

apiVersion: mirror.openshift.io/v2alpha1
kind: ImageSetConfiguration
mirror: 
  helm: 
    repositories: 
      - name: openshift-charts
        url: https://charts.openshift.io
        charts: 
          - name: redhat-developer-hub
            version: "1.4.1"

Actual results

• With v2 (latest from the main branch of oc-mirror), oc-mirror fails with the following logs:

  2025/07/23 14:51:00  [INFO]   : 👋 Hello, welcome to oc-mirror
  2025/07/23 14:51:00  [INFO]   : ⚙️  setting up the environment for you...
  2025/07/23 14:51:00  [INFO]   : 🔀 workflow mode: mirrorToDisk 
  2025/07/23 14:51:00  [INFO]   : 🕵  going to discover the necessary images...
  2025/07/23 14:51:00  [INFO]   : 🔍 collecting release images...
  2025/07/23 14:51:00  [INFO]   : 🔍 collecting operator images...
  2025/07/23 14:51:00  [INFO]   : 🔍 collecting additional images...
  2025/07/23 14:51:00  [INFO]   : 🔍 collecting helm images...
  2025/07/23 14:51:04  [INFO]   : mirror time     : 3.998246512s
  2025/07/23 14:51:04  [INFO]   : 👋 Goodbye, thank you for using oc-mirror
  2025/07/23 14:51:04  [ERROR]  : [Executor] collection error: failed to get template redhat-developer-hub: error rendering chart redhat-developer-hub: template: redhat-developer-hub/templates/tests/test-connection.yaml:38:166: executing "redhat-developer-hub/templates/tests/test-connection.yaml" at <.Values.upstream.service.ports.backend>: nil pointer evaluating interface {}.backend
  

• With v1 (I know it is deprecated), it doesn't fail but doesn't do anything:

  Creating directory: mirror-archive/oc-mirror-workspace/src/publish
  Creating directory: mirror-archive/oc-mirror-workspace/src/v2
  Creating directory: mirror-archive/oc-mirror-workspace/src/charts
  Creating directory: mirror-archive/oc-mirror-workspace/src/release-signatures
  backend is not configured in .asoro/airgap/my-image-set-configuration.yaml, using stateless mode
  backend is not configured in .asoro/airgap/my-image-set-configuration.yaml, using stateless mode
  No metadata detected, creating new workspace
  Pulling chart redhat-developer-hub
  error image list []
  No new images detected, process stopping
  

Expected results

oc-mirror should be able to mirror charts that are using an aliased dependency, as this can be quite common.

Additional info

Fix contributed in https://github.com/openshift/oc-mirror/pull/1038