codex/third_party/v8

rusty_v8 Consumer Artifacts

This directory wires the v8 crate to exact-version Bazel inputs. Bazel consumer builds use:

• upstream denoland/rusty_v8 release archives on Windows MSVC
• source-built V8 archives on Darwin, GNU Linux, musl Linux, and Windows GNU

Local Cargo builds still use upstream prebuilt rusty_v8 archives by default. Selected Cargo CI, release, and package builds override RUSTY_V8_ARCHIVE/RUSTY_V8_SRC_BINDING_PATH with Codex release assets. Bazel sets those variables independently in MODULE.bazel to select source-built local archives and bindings for its consumer builds.

The Bazel v8 crate feature selection enables V8's in-process sandbox for Darwin, Linux, and Windows GNU. Windows MSVC remains on upstream non-sandboxed prebuilts.

Current pinned versions:

• Rust crate: v8 = =150.4.0
• Embedded upstream V8 source for Bazel-produced release builds: 15.0.245.2

Updating to a new v8 release

Use this as the maintainer flow for a version bump:

1. Bump the v8 crate version and refresh codex-rs/Cargo.lock.
2. Update the Bazel versioned inputs in MODULE.bazel, then refresh the matching checksum manifest and generated checksums as described below.
3. Publish a release-candidate PR and validate that v8-canary passes.
4. If the canary is green, publish the release tag and release build.
5. Independently verify the published Codex-built checksum manifests and record their SHA-256 digests in third_party/v8/rusty_v8_<version>_release_manifests.sha256.
6. Once the release build completes, rerun the build on the candidate branch and verify that the final artifact builds and tests pass.

When changing the remaining prebuilt rusty_v8 http_file inputs, keep the checked-in checksum manifest and MODULE.bazel in sync:

python3 .github/scripts/rusty_v8_bazel.py update-module-bazel
python3 .github/scripts/rusty_v8_bazel.py check-module-bazel

The commands default to the single rusty_v8_* http_file version still present in MODULE.bazel and validate every matching entry. CI runs the check command to block checksum drift.

The consumer-facing selectors are:

• //third_party/v8:rusty_v8_archive_for_target
• //third_party/v8:rusty_v8_binding_for_target

Published release assets are expected at the tag:

• rusty-v8-v<crate_version>

with these raw asset names:

• librusty_v8_release_<target>.a.gz
• src_binding_release_<target>.rs

During the sandbox rollout, sandbox-enabled assets are published alongside those current assets on the same tag, with the Rust crate's sandbox feature suffix in their raw names:

• librusty_v8_ptrcomp_sandbox_release_<target>.a.gz
• rusty_v8_ptrcomp_sandbox_release_<target>.lib.gz on Windows MSVC
• src_binding_ptrcomp_sandbox_release_<target>.rs

The dedicated publishing workflow is .github/workflows/rusty-v8-release.yml. Tagged runs build release artifacts from the Bazel graph itself:

• //third_party/v8:rusty_v8_release_pair_x86_64_apple_darwin
• //third_party/v8:rusty_v8_release_pair_aarch64_apple_darwin
• //third_party/v8:rusty_v8_release_pair_x86_64_unknown_linux_gnu
• //third_party/v8:rusty_v8_release_pair_aarch64_unknown_linux_gnu
• //third_party/v8:rusty_v8_release_pair_x86_64_unknown_linux_musl
• //third_party/v8:rusty_v8_release_pair_aarch64_unknown_linux_musl

The same run also builds the matching sandbox pair targets:

• //third_party/v8:rusty_v8_sandbox_release_pair_x86_64_apple_darwin
• //third_party/v8:rusty_v8_sandbox_release_pair_aarch64_apple_darwin
• //third_party/v8:rusty_v8_sandbox_release_pair_x86_64_unknown_linux_gnu
• //third_party/v8:rusty_v8_sandbox_release_pair_aarch64_unknown_linux_gnu
• //third_party/v8:rusty_v8_sandbox_release_pair_x86_64_unknown_linux_musl
• //third_party/v8:rusty_v8_sandbox_release_pair_aarch64_unknown_linux_musl

The workflow also builds sandbox-enabled x86_64-pc-windows-msvc and aarch64-pc-windows-msvc archive/binding pairs from upstream rusty_v8 source. Those ABI-specific outputs cannot be produced by Codex's Bazel Windows GNU toolchain.

The Bazel graph pins the same libc++, libc++abi, and llvm-libc source revisions used by rusty_v8 v150.4.0, compiles published artifact targets with --config=rusty-v8-upstream-libcxx, and folds the matching runtime objects into the final static archive so consumers can link it with the v8 crate's default use_custom_libcxx feature. The config keeps the object files and the bundled runtime on Chromium's std::__Cr ABI namespace instead of mixing those objects with the toolchain libc++ default namespace. Bazel consumers use these source-built targets directly; Cargo release and package builds use the published copies.

MSVC is not part of the Bazel-produced matrix yet. The repository's current hermetic Windows C++ platform is windows-gnullvm/x86_64-w64-windows-gnu, so it cannot truthfully reproduce upstream's *-pc-windows-msvc archives until we add a real MSVC-targeting C++ toolchain to the Bazel graph.

Release and CI Cargo builds for Darwin and Linux use RUSTY_V8_ARCHIVE plus a downloaded RUSTY_V8_SRC_BINDING_PATH to point at those openai/codex release assets directly. We do not use RUSTY_V8_MIRROR because the upstream v8 crate hardcodes a v<crate_version> tag layout, while our artifacts are published under rusty-v8-v<crate_version>.

Do not mix artifacts across crate versions. The archive and binding must match the exact resolved v8 crate version in codex-rs/Cargo.lock.