agent: builder model: opus max_turns: 120 budget_usd: 22 effort: medium —
Score: the language topics (owner, 2026-11-03), ADR-async-5 is the record. Rust is allowed (#1214) where the code is Rust; .nika stays Nikaia. a5 (a5-async-value-lowering.md, read it whole: its To build, tests and Done when are yours) ran out of turns twice. Read its retrospective a5-async-value-lowering.debrief.md before anything else.
Surface today: a5 left its work uncommitted in the shared checkout: crates/nikaia-std/src/task.rs, task/group.rs, and emit_core_args, emit_expr, emit_function, emit_function_body, emit_state and emit_stmt (.nika + lowered/*.rs). git diff on those files is your starting point. Steps 1 and 2 of a5 are built there and their probes pass, except the unread-failure test. Its 9 test programs were run from a scratchpad copy that is gone, so you write them again (5 new, 4 converted from a4’s tests/compiler/tests/async_*).
Facts (from a5’s retrospective):
From<Crashed> + Joined. Only nikaia_std::task::Crashed, Box, and generated throw sums __NikaiaThrows_… that hold task::Crashed have them. emit_sums.nika writes those impls only when task::Crashed is in the throw set. emit_call_tasks_channel (emit_core_args.nika) picks the channel.task::Crashed into an inferred throw set for task::scope, but not for async. That is defect 1.async { … } used as a statement. Probe: fn main() { async { async work(1) } println("x") }. That is defect 2.CheckAsyncWait: the group id is encoded as -1 - stmts[0].span.start. id.get() is u32 and the facts are keyed i64.user_parallelism: yes is not built, so both settings run in sequence. Say so in the commit message, not as a deviation.Ok({ 4 }) trips unused_braces.nikaia run. Run it with nikaia test tests/compiler --filter <name>.Owns:
async { }.Not yours: as in a5.
tests/compiler/tests/async_*, shown failing on the binary before your fix):
(a) a function whose body starts async tasks gets task::Crashed in its inferred throw set, as task::scope does (Part II 12.7, ADR-async-5 D10);
(b) async { … } as a statement ends the statement like any block statement, so the next statement needs no ;.
Commit Part of #988.Part of #988 (one or two commits).List under Body: every Rust function you added or changed, for #557 / #125.
A further defect: no third fix, file nothing, report it under Found: with its probe.
Rs2nika: none.
As a5’s Done when, plus the two defect tests.
an existing task::scope, spawn or overlap program changes output; fix 1 changes an existing program’s throw set beyond adding task::Crashed where async tasks start.
docs/builder-facts.md first. You work in /home/user/Nikaia on develop (the shared checkout). Build with CARGO_INCREMENTAL=0 cargo build --profile fast -p nikaia; use only /home/user/Nikaia/target/fast/nikaia.git add <files> only, never -a/-A; commit after each step. Never git reset, stash, checkout ., restore .; restore only your own files by name. An error in another agent’s file is escalated, not touched.lower-std changed, yours and others’. Do not edit docs/selfhosting-plan.md, docs/architect.md, docs/priorities.md, docs/bootstrap.md or scripts/self_hosting.py: rows for them go into Body: of your report.cargo fmt, cargo clippy --all-targets -- -D warnings, nikaia run scripts/pre-push.nika, and the gate of .claude/agents/builder.md. You commit; the supervisor pushes.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; if df -h /home/user shows under 2 GB free, stop and report blocked. Never delete another checkout’s target/./home/user/Nikaia/docs/briefs/async/a5b-async-fixes-and-lowering.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 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 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:); 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