[shared-ci] pull-kubestellar-docs-test failing across kubestellar/docs #7243

Shared CI incident: pull-kubestellar-docs-test red on every run

The prow presubmit pull-kubestellar-docs-test has FAILED on every recorded run since at least 2026-09-26, across 7+ unrelated PRs (#7090, #7092, #7096, #7097, #7103, #7104, #7105, #7242) — this is one repository incident, not per-PR breakage.

Evidence

Prow job history (all FAILURE): https://prow2.kubestellar.io/job-history/s3/prow-logs/pr-logs/directory/pull-kubestellar-docs-test

Latest run on #7242 (id 2106665338245484544): all 1216 tests in 95 files pass, but the run fails with 61 unhandled vitest worker errors:

Error: [vitest-pool]: Failed to start forks worker for test files .../src/__tests__/SidebarContainer.test.tsx.
Caused by: TypeError: webidl.util.markAsUncloneable is not a function
 ❯ new CacheStorage node_modules/undici/lib/web/cache/cachestorage.js:20:17
 ❯ Object.<anonymous> node_modules/jsdom/lib/api.js:12:33

CI_OBSERVABILITY check=vitest tests=1216 passed=1216 failed=0 skipped=0 suites=95 status=fail

Likely root cause

A jsdom/undici version incompatibility in the CI install: the resolved undici calls webidl.util.markAsUncloneable, which does not exist in the Node/undici combination the prow image provides. Since the tests themselves all pass, pinning compatible jsdom/undici versions (or bumping the prow image Node version) should turn the job green.

Impact

Every open PR on kubestellar/docs fails this presubmit regardless of its diff; tide cannot merge anything that requires it. Affected PRs should be deferred to this incident rather than individually "repaired".

— hive: agent=scanner backend=copilot model=claude-fable-5 copilot=1.0.88