agent: builder model: sonnet max_turns: 80 budget_usd: 15 —
Score: a red develop is fixed forward first (CLAUDE.md); main stands still until then (last green c53ddd4). A compiler bug (the formatter is self-hosted), before any move.
bootstrap_compiler and arm64 fail one test only, fmt::every_nika_file_formats_to_the_same_tree_and_a_fixed_point (crates/nikaia/tests/it/fmt.rs:190; it formats every parsing .nika under examples tests benches crates/nikaia-std/src crates/nikaia/tests packages and fails on a guard refusal or a second pass that changes the text). The push before (c53ddd4) was green; 0f9a525 added crates/nikaia-std/src/tools/project_check.nika. P5b’s project_lower.nika formats fine.target/fast/nikaia fmt on a copy of project_check.nika: not formatted: the formatted file does not parse: Expected _ or identifier here, but found ). The first failing item is project_check_keeps_that_moved (lines 434-449), the line 440 chain.p.nika:
fn f(v: ref Vec[(String, bool)]) {
let m = v.iter().filter(fn((param, _)) { param != "self" && then.params.iter().any(fn((p, _)) { p == param }) }).filter_map(fn((param, ty)) {
return 1
}).collect()
}Formats fine: the same without the nested any(fn((p, _)) ...), or with fn(param) instead of fn((param, _)), or the short one-liner v.iter().filter(fn((a, _)) { w.iter().any(fn((q, _)) { q == a }) }).count(). So the long line is cut, and the cut lands inside a closure’s tuple pattern.
crates/nikaia-std/src/tools/fmt.nika (951 lines; crates/nikaia/src/fmt.rs:21 calls fmt_source). Likely place: fmt_sealed (:851) seals a pattern only when =>, |, = or in follows it, not a closure parameter pattern fn((a, b)), so fmt_breakable (:865) lets it go one per line with a trailing comma ((param, _,)). Confirm before fixing; fmt_bar_opens (:480) is the |...| analogue.println in a scratch build, or nikaia::fmt::format from a scratch it filter; nothing of that committed) and fix it in tools/fmt.nika: a closure’s parameter list and the tuple patterns in it stay sealed (no cut, no trailing comma). Run target/fast/nikaia lower-std (only lowered/fmt.rs may change), rebuild.tests/compiler/tests/fmt_keeps_a_nested_tuple_closure_whole.nika with the probe’s shape made runnable (a fn main that prints the count, its .stdout beside it; a line over 100 columns with the nested tuple-pattern closure followed by a multi-line closure). The it scan then covers it. Check: target/fast/nikaia fmt on a scratch copy of it and of project_check.nika formats (no refusal), and formatting the result again changes nothing.cargo test --profile fast -p nikaia --test it -- fmt:: passes (it fails before the fix on project_check.nika; say so under Tests:); nikaia test --project tests/compiler filtered to the new test passes; the gate of builder.md; clippy, cargo fmt, scripts/pre-push-check.sh. Commit: fmt: a closure's tuple pattern is not cut (fix-forward, CI red since 0f9a525), Fixes none. Changelog: one sentence (the formatter is the toolchain’s).
The cut is not in fmt.nika (then name where), or the fix changes the formatting of another .nika in the repository (run the fmt:: filter; a changed file elsewhere is a Deviation).
docs/builder-facts.md first. develop in the main checkout; git status at start: other agents’ uncommitted files are not yours, never touch or stage them.git add <files> only; commit after each step; git push origin develop fast-forward, no rebase (rejected: report Pushed: rejected, go on committing).cargo fmt, cargo clippy --all-targets -- -D warnings, scripts/pre-push-check.sh, and the gate of .claude/agents/builder.md (#852).CHANGELOG.md, badges; no new NK code. New tests in Nikaia only; never the full suite. No foreground sleep, no polling; scripts in files.NIKAIA_CACHE_LIMIT=2G; at most two clones with target/ in the machine; delete your own clone’s target/ and target/release/nikaia-scratch at the end; report GB freed./home/user/Nikaia/docs/briefs/b-fixforward-fmt-tuple-closure.md.report.md)Fields of docs/architect.md, Briefs and reports: Result: done|noop|partial|blocked (the bare word alone on that line: Result: done, never a summary after it, which cuts the batch, b869a 2026-10-27; Owner: is a question for the owner or none, never a role), Files, Commit, Body (optional, one paragraph for the commit message), Fixes, Pushed, Tests, Gate (green|red), Deviation, Found, Needs, Changelog, Owner, Disk freed, and for a move Rs2nika: (the kept N of M lines of rs2nika --score, then the three costliest hand edits; none for a task that moves no Rust, none (redesign) for a brief with Shape: redesign and no Convert: line). none where nothing, and then the bare word: Deviation: none (a note) cuts the batch (batch.nika compares exactly); a note goes into the commit message. Found: is only for a defect outside your change (it cuts the batch); a process event such as another session resetting or rewriting your files is no Found:, it goes under Needs: (m3a 2026-10-28); a converter draft that came out wrong is no Found:, it is one of the costliest edits under Rs2nika:, which the converter lane reads (e12-4b 2026-10-27); how you solved your own step goes into the commit message. Deviation: is only a step of the brief built otherwise than written or not built (a choice the brief left to you, such as keep what X needs and say so, is no deviation: it goes into the commit message; nor is building two steps in one commit when every step is built, e12-3a 2026-10-27, nor a step another commit on develop already built, shown by your test failing with that commit’s change reverted, b889 2026-10-27: name the commit in Body:, nor re-keying an allow-list entry (KNOWN) whose hash changed for the same program and the same reason, b-fixforward-sweep2 2026-10-28: say so in Body:); how you verified (e.g. a test not run against the unfixed compiler) goes under Tests:. A noop says why under Tests: (what was probed), not under Deviation:. Final answer, one line: done <sha>, report <path> (or BLOCKED: ... / PUSH REJECTED ...).
Attribution: Co-Authored-By: Claude Opus 5.5 noreply@anthropic.com Claude-Session: https://claude.ai/code/session_01GFeMqxRbtUMiGVyDMxsvEq