## Why
The Codex package builder should produce a complete package without
requiring callers to pre-populate `rg` under `codex-cli/vendor` or have
`dotslash` installed on `PATH`. The repo already tracks the
authoritative DotSlash manifest in `codex-cli/bin/rg`, so the builder
can read that metadata directly and fetch the correct ripgrep archive
for the target it is packaging.
## What changed
- Added `scripts/codex_package/ripgrep.py` to parse `codex-cli/bin/rg`
after stripping the shebang, select the target platform entry, download
the configured artifact, and verify the recorded size and SHA-256
digest.
- Added a cache under `$TMPDIR/codex-package/<target>-rg` so verified
archives can be reused without fetching again.
- Extracted `rg`/`rg.exe` from `tar.gz` and `zip` artifacts into the
package-builder cache, then copied that into `codex-path` through the
existing package layout flow.
- Kept `--rg-bin` as an explicit local override for offline tests and
unusual local workflows.
- Documented the default `rg` fetch/cache behavior in
`scripts/codex_package/README.md`.
## Verification
- Ran wrapper/module syntax compilation.
- Ran `scripts/build_codex_package.py --help` from `/private/tmp`.
- Ran a local manifest fetch test covering shebang-stripped manifest
parsing, `tar.gz` extraction, `zip` extraction, size/SHA-256
verification, and cache reuse after deleting the original source
archives.
- Ran fake-cargo package/archive builds for macOS, Linux, and Windows
target layouts with `--rg-bin`, including an assertion that generated
tar archives contain no duplicate member names.
---
[//]: # (BEGIN SAPLING FOOTER)
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with [ReviewStack](https://reviewstack.dev/openai/codex/pull/23526).
* #23541
* __->__ #23526
