(Feel free to update this bug's summary to be more specific.)
Component Readiness has found a potential regression in the following test:

[sig-cluster-lifecycle][OCPFeatureGate:VSphereMultiNetworks][platform:vsphere] Managed cluster should new machines should pass multi network tests [Serial][apigroup:machine.openshift.io][Suite:openshift/conformance/serial]

Extreme regression detected.
Fishers Exact probability of a regression: 100.00%.
Test pass rate dropped from 100.00% to 84.00%.

Sample (being evaluated) Release: 4.21
Start Time: 2025-11-10T00:00:00Z
End Time: 2025-11-17T12:00:00Z
Success Rate: 84.00%
Successes: 21
Failures: 4
Flakes: 0
Base (historical) Release: 4.20
Start Time: 2025-10-18T00:00:00Z
End Time: 2025-11-17T12:00:00Z
Success Rate: 100.00%
Successes: 99
Failures: 0
Flakes: 0

View the test details report for additional context.

20 regressions resulting from a batch of test failures back to back, the issue seems now resolved.

The failures all seem to report:

{  cannot clone suite after tree has been built

external binary did not produce a result for this test}

This card is mostly for tracking.

Filed by: dgoodwin@redhat.com