Update V8 Version Skill for Codex

Update V8 Version

Core Workflow

• Read third_party/v8/README.md and follow its version-bump sequence. Treat

that document as the release-process source of truth.

• Inspect and update the concrete repo surfaces that carry the pin:
• codex-rs/Cargo.toml
• codex-rs/Cargo.lock
• MODULE.bazel
• third_party/v8/BUILD.bazel
• third_party/v8/README.md
• the matching third_party/v8/rusty_v8_<version>.sha256 manifest when the

remaining prebuilt inputs change

• Keep the existing checksum helpers in the loop:

   python3 .github/scripts/rusty_v8_bazel.py update-module-bazel
   python3 .github/scripts/rusty_v8_bazel.py check-module-bazel
   python3 -m unittest discover -s .github/scripts -p test_rusty_v8_bazel.py

• Validate the release-candidate path before broadening the work:
• Prefer checking the v8-canary CI result for the candidate branch or PR

when one exists, using GitHub check tooling or gh as appropriate.

• If CI is unavailable or the user asked for a local-only check, run the

closest local validation that is practical for the changed surface and say

explicitly that it is a local substitute, not the full hosted canary.

• If the canary path passes, stop there. Summarize the result and encourage the

user to commit the candidate changes or proceed with the release flow they

requested. Do not publish tags, releases, or pushes unless the user asked.

Failure Path

Enter this path only when the canary or local build path fails.

• Capture the failing target, workflow job, and first actionable error.
• Compare the currently pinned version with the target version at the relevant

upstream tag or SHA. Inspect both:

• denoland/rusty_v8
• upstream V8 source at the target Bazel-pinned version
• Track build-relevant deltas rather than broad source churn:
• generated binding layout changes
• archive or asset naming changes
• GN/Bazel target changes
• custom libc++ / libc++abi / llvm-libc inputs
• sandbox or pointer-compression feature relationships
• patch hunks in patches/ that no longer apply or no longer match upstream
• Trace each failing delta back into Codex's build graph:
• MODULE.bazel
• third_party/v8/BUILD.bazel
• .github/scripts/rusty_v8_bazel.py
• .github/workflows/v8-canary.yml
• .github/workflows/rusty-v8-release.yml
• Update only the pieces required to restore the target version's build and

artifact contract. Keep patch explanations and doc changes close to the

affected files.

• Re-run the focused validation. If it becomes green, return to the normal

workflow and stop with a concise summary plus the remaining release step.

Reporting

• Say whether validation came from hosted v8-canary or from a local

substitute.

• Distinguish "version bump complete" from "release published".
• When blocked, report the upstream delta that matters, the Codex file it hits,

and the next concrete fix to try.