While preparing to upgrade 3542 SNOs via IBU, 1 failed prep phase with the following error message:

# oc --kubeconfig /root/hv-vm/kc/vm03544/kubeconfig get ibu
NAME      AGE   DESIRED STAGE   STATE    DETAILS
upgrade   22h   Prep            Failed   prep stage failed with error from prep worker: encountered error while running prep-stage worker goroutine: failed to validate IBU spec: failed to validate seed image OCP version: failed to parse seed version :  is not in dotted-tri format

LCA Operator - lifecycle-agent.v4.15.2
ACM  - 2.10.2-DOWNSTREAM-2024-04-12-21-01-39
Hub OCP - 4.15.9
Spoke Clusters originally deployed as 4.14.14, IBU to 4.14.16 then to 4.15.2 and finally to 4.15.9 (Failure occurred on prep from 4.15.2 to 4.15.9)

Rare - 1 out of 3542 (Only time observed this prep failure from several prep phase runs)

    1.
    2.
    3.
    

# oc --kubeconfig /root/hv-vm/kc/vm03544/kubeconfig get ibu upgrade -o yaml
apiVersion: lca.openshift.io/v1alpha1
kind: ImageBasedUpgrade
metadata:
  creationTimestamp: "2024-04-24T14:10:02Z"
  generation: 3
  name: upgrade
  resourceVersion: "305004"
  uid: f2ae6ede-a25f-4b16-ae04-d491940c4bd4
spec:
  additionalImages:
    name: ""
    namespace: ""
  autoRollbackOnFailure:
    disabledForPostRebootConfig: true
    disabledForUpgradeCompletion: true
    disabledInitMonitor: true
  oadpContent:
  - name: oadp-cm
    namespace: openshift-adp
  seedImageRef:
    image: d16-h01-000-r650.rdu2.scalelab.redhat.com:5000/openshift-kni/ocp-ibu:4.15.9.ibu-x86_64
    pullSecretRef:
      name: seedgen
    version: 4.15.9
  stage: Prep
status:
  conditions:
  - lastTransitionTime: "2024-04-24T23:24:02Z"
    message: In progress
    observedGeneration: 3
    reason: InProgress
    status: "False"
    type: Idle
  - lastTransitionTime: "2024-04-24T23:24:32Z"
    message: Prep failed
    observedGeneration: 3
    reason: Failed
    status: "False"
    type: PrepCompleted
  - lastTransitionTime: "2024-04-24T23:24:32Z"
    message: 'prep stage failed with error from prep worker: encountered error while
      running prep-stage worker goroutine: failed to validate IBU spec: failed to
      validate seed image OCP version: failed to parse seed version :  is not in dotted-tri
      format'
    observedGeneration: 3
    reason: Failed
    status: "False"
    type: PrepInProgress
  observedGeneration: 3
  validNextStages:
  - Idle