When an invalid custom osImage is configured in MCO, the reported error is empty  "%!w(<nil>)"

4.21.0-0.nightly-2025-10-30-125804    

    Always

    1. Enable Techpreview

$ oc patch featuregate cluster --type=merge -p '{"spec":{"featureSet": "TechPreviewNoUpgrade"}}'

    2. Create a MC to deploy an invalid custom osImage

$ cat << EOF | oc create -f -
 kind: MachineConfig
 apiVersion: machineconfiguration.openshift.io/v1
 metadata:
   labels:
     machineconfiguration.openshift.io/role: "worker"
   name: "not-bootable-image-tc54052"
 spec:
   osImageURL: "quay.io/openshifttest/hello-openshift:1.2.0"
EOF
    

    4. Wait for the mcp to become degraded

    The reported error is empty: %!w(<nil>)"

$ oc get mcp worker -oyaml
...

  - lastTransitionTime: "2025-10-31T10:55:01Z"
    message: 'Node ip-10-0-20-14.us-east-2.compute.internal is reporting: "Node ip-10-0-20-14.us-east-2.compute.internal
      upgrade failure. Failed to update OS to quay.io/openshifttest/hello-openshift:1.2.0
      after retries: %!w(<nil>)", Node ip-10-0-20-14.us-east-2.compute.internal is
      reporting: "Failed to update OS to quay.io/openshifttest/hello-openshift:1.2.0
      after retries: %!w(<nil>)"'     reason: ""
    status: "True"
    type: Degraded

    The degraded message should show the right error causing the problem

It looks like it is related to https://issues.redhat.com/browse/OCPBUGS-52302