[kixelated]

Problem

Hosted R2 cache verification is incomplete. The scheduled macOS platform jobs refuse task action manifests that mbx wrote past its own 16 MiB reader bound, so those tasks get no remote predictions, and no hosted job shows remote reuse yet.

Approach

Upstream report jdx/mr-boxington#792 is closed, fixed by jdx/mr-boxington#798 (commit 9c8d3c7). It caps a task manifest at a 15 MiB serialized budget and keeps the 16 MiB read bound. It merged 27 minutes after v1.27.0 was published, so no release carries it; the open release PR jdx/mr-boxington#797 proposes it as 1.27.1. The pin in .github/actions/rust-cache/action.yml therefore stays at 1.25.0, the hold from #6515.

The quest changes:

• New quest/m0/ci/mbx-bump.md [XS]: waits for an mbx release containing CPU Maxed Out #798 (checkable with a compare call), then bumps the pin. That release also carries jdx/mr-boxington#789, which ci: hold the Rust cache at mbx 1.25 #6515 named as the upgrade condition for its 1.26 E0463 hold. CPU Maxed Out #798 does not repair manifests already oversized on R2; they stay stuck until the 30-day lifecycle deletes them, about 2026-11-22 at the latest.
• quest/m0/ci/mbx-r2-verify.md now requires the bump, drops the met bootstrap condition, and records evidence from Nightlies 39600361153, 39779729461 and 39951870847. The 2026-10-23 run on mbx 1.26.0 still refuses manifests, adding a third digest (b0310ce4..., 17228175 bytes).
• Windows refuses nothing but still reuses nothing: 0 hits, and 1084 of 1091 compilations had no matching prediction to look up, a day after a 1.25.0 Nightly wrote. The manifest fix does not explain this, so the quest says to find why before timing builds if it persists after the bump.

The remaining gates are unchanged and unproven: consecutive hosted remote reuse, a release PR's effective read-only (no release PR has used R2 yet), comparable build timing, and a full month of bucket, request, and expiry data. They wait on the upstream release and on elapsed time. Only scheduled runs were used; nothing was dispatched.

Impact

• Public API and wire: none. Quest files only.
• No cache policies, limits, secrets, schedules, or pins change.

Alternatives

• Bump to 1.27.0 now: it carries Add HLS import module #789 but not CPU Maxed Out #798, so the macOS refusals continue. Upgrading past the ci: hold the Rust cache at mbx 1.25 #6515 hold is the bump quest's job, done once with both fixes.
• Delete the three oversized manifests from R2 by hand: would recover those tasks before the lifecycle does, but it is a manual bucket mutation, and it only helps once a release with CPU Maxed Out #798 is pinned.

Validation

nix develop --command just check passed (quest graph of 574 documents, Markdown, shell, TOML, Nix, justfiles, workflow checks). quest check --base origin/main passed.

Follow-ups

quest/m0/ci/mbx-bump.md is ready as soon as an mbx release contains #798.

(Written by Claude Opus 5.5)

🤖 Generated with Claude Code

[kixelated]

Verification checkpoint pushed as 8d55783 after nix develop --command just ci and git diff --check passed. The linked macOS Nightly has effective read-write credentials but repeats the exact 17,204,435-byte task-manifest refusal and reports zero downloaded bytes in all eleven cache summaries. The quest retains the failed verification and the remaining observations. This draft's ## Decisions needed records the upstream-post approval and unfinished hosted reuse/month-retention work. No cache policy, cap, secret, schedule, or dependency pin changed; no external report was sent.

(Written by GPT-6)

[kixelated]

Filed upstream as jdx/mr-boxington#792 (oversized task action manifest: the producer prunes by entry count, the reader caps at 16 MiB, and the stuck object blocks later uploads too). Both observed Nightlies ran mbx 1.25.0; the code involved is unchanged in 1.26.0 and upstream main. The 2026-10-22 Nightly hit a second task the same way (5cb8fb79..., 17213760 bytes).

(Written by Claude Opus 5.5)

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[chatgpt-codex-connector]

Codex Review Summary

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Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-23T16:03:12.990707Z	0dc40f2	Draft marked ready

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Reviewed commit: 0dc40f2ee6

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[kixelated]

Merging. The maintainer approved the split: a waiting quest for the mbx release that carries jdx/mr-boxington#798, with the verify quest rewritten to what remains. Codex reviewed the previous head; the only later commit is the trivial one-line fix for its finding (--event schedule). CI is green, the current head has a non-Grok review, and quest check passes against main.

(Written by Claude Opus 5.5)