agent: builder model: opus max_turns: 80 budget_usd: 15 —
Score: compiler bug, false acceptance (nikaia check passes, rustc refuses with a message no Nikaia source maps to); bugs-first default of docs/priorities.md. Filed by the bug lane’s architect, not held by it (ready, no wip).
fn pair(s: String) -> (String, i64) {
return (s.trim(), 1)
}
fn main() {
let p = pair(f" ab{1} ")
println(f"{p.0}")
let (k, n) = pair(f" cd{2} ")
println(f"{k} {n}")
}Expected ab1, cd2 1. Re-run by the architect on the fast binary of 08:06 (after #999’s e064b36e): rustc temporary value dropped while borrowed at gen:113, twice. Lowered fn pair(s: &str) -> (&str, i64), called pair(&format!(..)). With a String result the argument goes into a keep ((&__keep_N).put(format!(..)), ADR-283 D24); with a named argument the tuple form works.
Traced: made_arguments (crates/nikaia-std/src/tools/buffers.nika:1632) makes an argument made in the call a source only when the callee’s result is a view or a struct of views: if !result.is_a_view() && !a_struct_of_views(result, ask) { return } (:1636). A tuple result with a view part is neither, so no Source::Argument, no plan entry (plan.calls :1993), and argument_keep (emit_keeps.nika:97, asked at emit_core_args.nika:468) finds nothing.
buffers.nika:1632 made_arguments, :1636 the test, :1686 a_struct_of_views; ty.nika:1416 Ty::is_a_view.emit_keeps.nika:97 argument_keep; emit_core_args.nika:468 (should need no change).crates/nikaia-std/src/tools/lowered/ (buffers.rs), regenerated by lower-std.made_arguments also takes a tuple any part of which is a view or a struct of views (and the same through an optional, T?, if the contract carries one: probe fn first(s: String) -> (String, i64)? and add it to the test only if it fails today for the same reason; otherwise leave it out and say so under Tests:). Check first what the contract’s result type of pair is (ref String part or not) with nikaia lower / the ledger, and say it in Body:.tests/compiler/tests/a_tuple_result_keeps_its_temporary_argument.nika + .stdout with the program above, failing on the unfixed binary. Commit buffers: a tuple result with a view part keeps the argument made in the call (Fixes #1036).The test passes through nikaia test and fails on the unfixed compiler; the tests nikaia run scripts/where.nika -- made_arguments a_struct_of_views lists pass; lower-std fixpoint clean; cargo build --profile fast -p nikaia; the guard set of .claude/agents/builder.md green; pushed. Changelog: one line (a function returning a tuple with a view of an argument made in the call keeps that argument, instead of rustc’s “temporary value dropped while borrowed”). Stop about 15 turns before max_turns, commit what is finished and report partial.
An edit is needed outside buffers.nika, ty.nika, emit_keeps.nika, their lowered twins (and lowered.rs), files lower-std rewrites because of your change, and the new test; an error in another agent’s file. tests/compiler failures from a binary vanishing mid-run (another agent rebuilding) are not yours: run the named tests singly instead.
Not yours, never stage: every file git status shows modified or untracked at your start (today among them crates/nikaia/src/parser/mod.rs, crates/rs2nika/convert/*, a stray file whose name starts ork in the tree)), and every docs/briefs/* file except your report.
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.std or the toolchain lacks stops the work: no code around it unless an ADR or Part I-III refuses it (name it). Else Result: blocked, Found: gap + probe, Needs: owner decision (CLAUDE.md, A missing form stops the work).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.Pushed: line names the pushed sha. A report without a Pushed: line, or with a placeholder left in (TC, DISK), is not done and cuts the batch (k3a1 2026-10-29: Result: done, nothing committed)./home/user/Nikaia/docs/briefs/b1036-tuple-result-keeps-arg.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 a test’s expected .stdout/.stderr taken from what the program really prints where the brief’s sketch of it was short or wrong, b934 2026-10-29: say so in Body:, nor a lowering that follows the ADR governing it where the brief’s expected lowering contradicts that ADR, b933 2026-10-29: name the ADR in Body:, nor a lowering other than the brief’s where rustc cannot take the brief’s, b1029 2026-10-31: say why 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:, nor an existing test’s expected .stdout/.stderr updated because your change rightly changes the message it prints, b1012b 2026-10-31: name the test 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