Skip to content

ADR-0635 — CI Warning Omnibus (2026-05-19)

Status: Accepted Date: 2026-05-19 Deciders: lusoris PR: chore/ci-warning-omnibus

Context

CI run 26111553607 (workflow_dispatch on master, 2026-05-19) surfaced five warnings and notices that will become hard failures or day-zero breakage before the next scheduled merge window:

  1. Node.js 20 deprecation — ilammy/msvc-dev-cmd@v1.13.0 (pinned SHA 0b201ec74fa43914dc39ae48a89fd1d8cb592756) uses the Node.js 20 runtime. GitHub Actions will force Node.js 24 by default starting 2026-06-02 and remove Node.js 20 from runners on 2026-09-16. Surfaced on both Windows GPU build legs (MSVC + CUDA and MSVC + oneAPI SYCL).

  2. windows-latest redirect — GitHub will redirect windows-latest to windows-2025-vs2026 on 2026-06-15. All three Windows build legs (windows, windows-gpu-build) use runs-on: windows-latest.

  3. MoltenVK vulkaninfo warning — the advisory macOS Vulkan lane emits ::warning::vulkaninfo did not report MoltenVK/Apple GPU because hosted macOS runners do not expose bare-metal GPU access, so vulkaninfo cannot enumerate the Apple GPU even though the MoltenVK ICD loads correctly and the build+smoke-test pass. This warning surfaces as a CI annotation on every run.

  4. Cache entry deserialization failed — the macOS Vulkan lane's ccache restore step logs WARNING: Cache entry deserialization failed, entry ignored. Root cause: cached entries created by actions/cache@v4 cannot be deserialized by actions/cache@v5 (format changed). Old entries expire naturally over 7 days but produce noisy warnings until then. Bumping the cache-key version prefix forces clean entries.

  5. docs/mcp/tools.md#run_benchmark anchor failure — mkdocs build --strict fails because the heading ## \run_benchmark`generates an anchor that mkdocs-material's strict link validator cannot match against the cross-link indocs/mcp/index.md. PR #1431 added an HTMLtag as a workaround, but mkdocs-material's validator only sees heading-generated slugs, not rawtags. The real fix is to drop the backticks from the heading and drop the` tag.

Decision

Fix 1 — Replace ilammy/msvc-dev-cmd with TheMrMilchmann/setup-msvc-dev@v4

ilammy/msvc-dev-cmd has not shipped a Node.js 24 release as of 2026-05-19; the latest tag remains v1.13.0 (Node.js 20). TheMrMilchmann/setup-msvc-dev v4.0.0 (released 2025-09-01) uses node24 as its runtime and provides the same functional contract: runs vcvarsall.bat and exports PATH/INCLUDE/LIB for cl.exe. No input parameters are required for the default amd64 toolchain. Pinned to SHA 79dac248aac9d0059f86eae9d8b5bfab4e95e97c per helpers:pinGitHubActionDigests in renovate.json.

Fix 2 — Pin runs-on to windows-2025

Changed runs-on: windows-latest to runs-on: windows-2025 on both the windows (MinGW64) and windows-gpu-build (MSVC + CUDA/SYCL) jobs. The windows-2025 label is the current stable Windows Server 2025 image (equivalent to the current windows-latest — the redirect target is windows-2025-vs2026 which carries VS2026 IDE tooling we do not need). This change is a no-op today and prevents the day-zero redirect surprise on 2026-06-15.

Fix 3 — Demote MoltenVK vulkaninfo annotation to ::debug::

On hosted macOS runners, vulkaninfo writes GPU-capability warnings to stderr even when MoltenVK enumeration succeeds. Redirecting stderr to /dev/null (2>/dev/null) prevents those lines from surfacing as CI annotations. The grep on stdout remains the actual correctness gate; when it fails, the message is emitted at ::debug:: level (visible only with ACTIONS_RUNNER_DEBUG=true) with a note that this is expected on hosted runners without bare-metal GPU access. Because the lane is already continue-on-error: true, no correctness signal is lost.

Fix 4 — Bump ccache key version prefix to ccache-v2-

Changing the cache-key prefix from ccache- to ccache-v2- forces all consumers to start a cold cache, discarding the stale v4-format entries that caused the deserialization warning. The 7-day warm-up cost is acceptable given the deserialization warning surfaces on every macOS Vulkan run.

Fix 5 — Remove backticks and <a id> from ## run_benchmark heading

The heading ## \run_benchmark`causes mkdocs-material strict mode to reject the cross-linktools.md#run_benchmarkinindex.md. The root cause is that the strict validator resolves anchors from heading slugs, not from raw HTMLtags. Renaming to## run_benchmark(no backticks) produces slugrun_benchmark, which matches the existing cross-link without any change toindex.md. Thetag and itsmarkdownlint-disable` comment are removed as they are no longer needed.

Alternatives considered

Alternative Reason rejected
Bump ilammy/msvc-dev-cmd SHA to HEAD HEAD (460a772e4cf7358f9f2f23773240813e40e7a894) is still Node.js 20 — the action author has not released a Node.js 24 build
Set FORCE_JAVASCRIPT_ACTIONS_TO_NODE24=true Treats the symptom; the action may behave unexpectedly under a forced runtime it was not tested against
Use microsoft/setup-msbuild@v2 Exposes MSBuild, not the full MSVC dev command prompt; cl.exe would not be on PATH
Pin to windows-2025-vs2026 Ships VS2026 IDE tools not used by the build; slightly heavier image with no benefit
Keep windows-latest Day-zero breakage on 2026-06-15 when the redirect targets a different image
Keep ::warning:: on vulkaninfo Produces a CI annotation on every master push, training maintainers to ignore annotations
Suppress the deserialization warning by clearing the cache Requires a manual repo-settings operation; key-prefix bump is repeatable and reviewable in code
Wrap run_benchmark heading in a custom anchor directive mkdocs-material anchor directives are a paid-tier feature; not available on the fork's plan
Add backtick-heading support to mkdocs config There is no documented option to disable slug normalization

Consequences

  • The Windows GPU build legs no longer emit Node.js 20 deprecation annotations.
  • Windows builds are pinned to a stable image label that will not silently change on 2026-06-15.
  • The macOS Vulkan lane no longer emits spurious warning annotations.
  • The ccache deserialization warning disappears after the first warm-up run.
  • mkdocs build --strict passes for the run_benchmark anchor.
  • All ccache entries must rebuild from cold on the first run after this change (one-time wall-clock hit, ~3–5 min per affected cell).

References

  • req: "fix all CI warnings in one draft PR before they become hard failures"
  • Run 26111553607: libvmaf Build Matrix workflow_dispatch on master, 2026-05-19
  • TheMrMilchmann/setup-msvc-dev releases: v4.0.0 released 2025-09-01, Node.js 24
  • ilammy/msvc-dev-cmd latest: v1.13.0 (Node.js 20, no Node.js 24 release)
  • GitHub Actions runner images README: windows-2025 = current windows-latest image
  • ADR-0121: Windows GPU build-only legs original decision
  • ADR-0338: macOS Vulkan via MoltenVK advisory lane