[jeremy]

Follow-up to #932. Today's nixpkgs-unstable has removed ruby_3_3, which the dev shell pins, so flake.lock stayed on August's nixpkgs for v0.15.1. This moves Ruby to 3.4 everywhere it's pinned, and moves the lock.

• Ruby 3.3 → 3.4 in the three places that have to agree, since make check compiles the skill-eval patterns under Ruby's own regex engine: .mise.toml, both ruby/setup-ruby ruby-version inputs in test.yml (Integration Tests and Skill Evals), and ruby_3_4 in flake.nix's dev shell. CONTRIBUTING.md's requirement line follows.
• flake.lock: nixpkgs c27cdad4 (2026-08-27) → 5adc5083 (2026-10-20), the current nixpkgs-unstable head. Nix's Go goes from 1.26.7 to 1.26.9. vendorHash doesn't change.

Nix is still a patch behind the release binaries. go.mod's toolchain line asks for 1.26.10 (GO-2026-6809), and nixpkgs master has it, but unstable doesn't yet. buildGoModule builds with the Go nixpkgs gives it, so the flake builds with 1.26.9 until a later flake.lock bump takes Nix to Go 1.26.10 once unstable has it.

Verified on Linux x86_64, in the nixos/nix image scripts/update-nix-flake.sh pins:

• nix eval --raw .#devShells.x86_64-linux.default.drvPath resolves. With ruby_3_3 put back on the new lock, the same eval fails with nixpkgs' removal error, so the Ruby move is what makes the bump possible.
• scripts/nix-build-check.sh, the "Build the flake" step, passes with the existing vendorHash; the binary prints basecamp version 0.16.0, and go version on it reads go1.26.9.
• make check passes under Ruby 3.4.10, check-eval-patterns (199 patterns across 34 case files) and check-eval-harness included. The dev shell's ruby_3_4, 3.4.11 on this lock, compiles the same 199.

---

Summary by cubic

Moves the dev toolchain to Ruby 3.4 everywhere it's pinned and updates the flake to today's nixpkgs-unstable. nixpkgs-unstable removed ruby_3_3, which is why flake.lock was still pinned to August's nixpkgs.

The Ruby pins have to agree because make check compiles the skill-eval patterns under Ruby's own regex engine: .mise.toml, both ruby/setup-ruby inputs in test.yml, the dev shell's ruby_3_4 in flake.nix, and the requirement line in CONTRIBUTING.md all move to 3.4.

Notes

• The flake now builds with Go 1.26.9; go.mod's toolchain asks for 1.26.10, which nixpkgs master has but unstable doesn't yet, so a later flake.lock bump will pick it up.
• vendorHash is unchanged; the existing Nix build check passes with the new lock.

^{Written for commit 5292e49. Summary will update on new commits.}

[github-actions]

Sensitive Change Detection (shadow mode)

This PR modifies control-plane files:

• .github/workflows/test.yml

Shadow mode — this check is informational only. When activated, changes to these paths will require approval from a maintainer.

[chatgpt-codex-connector]

Codex Review Summary

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

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-21T20:10:46.362059Z	5292e49	Manual request

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[Copilot]

🔵 Needs a closer look

Nix builds remain on Go 1.26.9, identified in #932 as affected by GO-2026-6809, so the remaining security risk needs human acceptance.

No open issues 🎉

What changed in this PR

Updates Ruby to 3.4 across development and CI, allowing the nixpkgs-unstable refresh following #932.

Changes:

• Aligns Ruby pins and contributor requirements.
• Refreshes nixpkgs, moving Nix builds to Go 1.26.9; the Go 1.26.10 security update remains pending.

[!TIP]
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File	Description
flake.nix	Uses Ruby 3.4 in the development shell.
flake.lock	Updates the pinned nixpkgs revision.
CONTRIBUTING.md	Documents the Ruby 3.4 requirement.
.mise.toml	Pins local Ruby to 3.4.
.github/​workflows/​test.yml	Updates both CI Ruby pins to 3.4.

_{Review effort: Balanced}

[jeremy]

@codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Keep them coming!

Reviewed commit: 5292e493df

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• Comment "@codex review".

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[jeremy]

Flagged for human review — the remaining Go 1.26.9 exposure in Nix builds is a security trade-off for the author to accept or not, so it stays open.

What I checked on 5292e49:

• The Nix build compiles with go-1.26.9 (the Nix flake builds job pulls go-1.26.9 from cache.nixos.org). nixpkgs-unstable's channel is still at this lock's 5adc5083, with go_1_26 at 1.26.9, so no newer unstable lock exists to move to today.
• GO-2026-6809 (crypto/x509 Certificate.Verify, fixed in 1.26.10) is reachable from cmd/basecamp, the only package nix/package.nix builds. govulncheck under go1.26.9 traces it through the sigstore check in basecamp upgrade, and every HTTPS request verifies its chain through the same function.
• This PR doesn't introduce the exposure: main's lock builds Nix with 1.26.7, which is affected too. The PR moves Nix from 1.26.7 to 1.26.9 and leaves the CVE where it was.
• Dependabot here covers gomod, github-actions and docker, not the flake, so nothing bumps flake.lock once unstable picks up 1.26.10. A person or a lane has to.

Options:

1. Accept and merge as is, then bump flake.lock in a one-file follow-up once unstable carries 1.26.10 (master already does). This is my recommendation: the exposure is already on main, this PR narrows the Go gap, and the fix is a lock bump.
2. Hold this PR until unstable advances, then bump flake.lock here so it lands with 1.26.10.
3. Bridge now: override go_1_26 to 1.26.10 in nix/package.nix, so Nix CI and every Nix install compile Go from source until someone removes the override; or lock nixpkgs to a master revision, which the channel hasn't tested and the cache may not fully cover. I haven't tried either, because neither this Mac nor thelio has nix.

[jeremy]

Review threads: none on 5292e49.
Review bodies: 1 finding answered (0 fixed, 0 declined, 1 open for a decision).
Open for a decision: #935 (review), Copilot's note that Nix builds stay on Go 1.26.9 (GO-2026-6809). The author needs to choose: accept it with a follow-up flake.lock bump, hold this PR for unstable, or bridge Go in nix/package.nix. Options and evidence: #935 (comment)