[cknitt]

Stacked on #9208. Runs make dead-code in CI, so new dead code in the OCaml sources fails the build.

The check runs in the build-compiler job entry that builds the playground (ubuntu-26.04-arm, build_playground: true), right after the playground build. That entry has the browser-profile dependencies the check needs: it analyzes the native and the browser build trees together, so code used only by the playground counts as live.

It needs reanalyze 2.27.0, the first release that can analyze both trees together. The step clones the v2.27.0 tag, builds reanalyze with dune in the job's existing switch (seconds), and passes it to make dead-code through REANALYZE:

git -c advice.detachedHead=false clone --quiet --depth 1 --branch v2.27.0 https://github.com/rescript-lang/reanalyze.git "$RUNNER_TEMP/reanalyze"
opam exec -- sh -c 'cd "$RUNNER_TEMP/reanalyze" && dune build -p reanalyze @install'
REANALYZE="$RUNNER_TEMP/reanalyze/_build/install/default/bin/reanalyze.exe" opam exec -- make dead-code

Why not opam install reanalyze? The first version of this PR tried that. opam recompiled the whole restored switch (62 packages, about 4 minutes), because it misses the musl system package of the static switch and treats that as a system change. Building from the tag avoids touching the switch. (opam exec runs from the repository because the CI switch is local to it.) It also doesn't wait for the opam package (ocaml/opam-repository#31123), and works the same once that's published.

On this stack, make dead-code reports 0 issues with reanalyze 2.27.0, locally and in CI.

🤖 Generated with Claude Code

https://claude.ai/code/session_01Kbf3gLDo8mBJKpNE25WAwT

[github-actions]

Changelog

🏠 Internal

• Check in CI that reanalyze reports no dead code in the OCaml sources.

Semantic Diff

3 commits · Full page

Check for dead code in CI

_{6d640de · cknitt + Claude · Nov 06, 2026, 20:53 UTC}

The build-compiler job that builds the playground now runs make dead-code after the playground build, so new dead code fails CI. It installs reanalyze 2.27.0, the first release that analyzes the native and the browser build trees together, from its tag until the opam-repository package is merged.

Build reanalyze from its tag instead of installing it with opam

_{102f322 · cknitt + Claude · Nov 06, 2026, 21:27 UTC}

In CI, opam install reanalyze recompiled the whole restored switch (62 packages, about 4 minutes): opam misses the musl system package of the static switch and treats that as a system change. The step now clones the v2.27.0 tag and builds reanalyze with dune in the existing switch (seconds), and passes it to make dead-code with REANALYZE. This also works unchanged once the opam package is published.

✨ Run opam exec from the repository when building reanalyze

_{2f2adec · cknitt + Claude · Nov 06, 2026, 21:40 UTC · new}

CI's opam switch is local to the repository, and opam exec finds it from the current directory: run from inside the reanalyze clone it failed with "No switch is currently set". opam exec now runs from the repository and changes into the clone itself.

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commit: 2f2adec

[cknitt]

@codex review

[chatgpt-codex-connector]

Codex Review Summary: ✅ Completed

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-11-07T06:08:14.020114Z	2f2adec	Manual request

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[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. More of your lovely PRs please.

Reviewed commit: 2f2adec1af

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