agent: builder model: opus max_turns: 80 budget_usd: 16 —
Score: compiler bug, false acceptance (nikaia check passes, rustc Missing lifetime specifier), text and lists alike; one cause traced, one branch to widen.
Facts: Where things live, Traps already met, Commands
fn longer(a: ref String, b: ref String) -> ref String {
if a.len() >= b.len() {
return a
}
return b
}
fn apply(g: fn(ref String, ref String) -> ref String, a: ref String) -> i64 {
return g(a, a).len()
}
fn main() {
println(f"{apply(longer, "abc")}")
}Rows:
ref String are expected, leave them; in the test write String without ref if the probe still fails that way, and say so in Body:). Must print 3.ref Vec[i64] (longer(a: ref Vec[i64], b: ref Vec[i64]) -> ref Vec[i64], apply(longer, xs) with xs = [1, 2, 3]) - the same rustc error. Must print 3.3, must stay): row a with the parameter type written fn(ref String, ref String) -> ref String sync.g kept, not run: a struct field f: fn(ref String, ref String) -> ref String set to longer and called through the struct. Probe it first; if it fails with the same rustc error it is part of this fix, if it runs it is a guard row; say which under Tests:.crates/nikaia-std/src/tools/emit_core_types.nika, the code-type branch (from :131). The #703 branch (:152-189) writes for<'call> Fn(&'call str, &'call str) -> &'call str when the result is a view and more than one parameter is lent, but only under if code.is_sync && code.result != null. A function type without sync may pause, so it falls through to impl AsyncFn({params}) -> {outcome} (:230-232, walk.code_parameter_runs) or impl Fn(..) -> Pin<Box<dyn Future<Output = ..>>> (:233) with elided lifetimes, which rustc refuses for two lent inputs. That is why row c (sync) runs.lent > 1 and the result is a view, write the parameters and result with EmitLifetimes::Call under one for<'call>: impl for<'call> AsyncFn(&'call str, &'call str) -> &'call str for a run parameter; for the boxed-future form and the kept form (:206-216, emit_boxed_future_in, BoxedIn<'call, ..>) the outcome also takes 'call. Any lowering rustc accepts that keeps one lifetime over all lent parameters and the result (the caller’s result lives as long as the shorter one) is right; say in Body: which forms you wrote.a_list_read_as_a_slice as in the sync branch (#1016).Tests:.tests/compiler/tests/a_function_type_with_two_views.nika + .stdout: rows a, b, c (and d), one apply each, printing their answers. Commit emit: a function type that may pause, with two views in and a view out, names one lifetime (Fixes #1048).The new test fails on the unfixed compiler and passes through nikaia test --project tests/compiler --both-settings (by name); the tests/compiler tests whose names contain function_type, code_param or lambda pass (ls tests/compiler/tests | grep -E ..., run by name); lower-std fixpoint clean (no tools/*.nika change expected: lowered/emit_core_types.rs only); build, fmt, clippy, pre-push-check.sh; committed locally. Changelog: one line. Stop about 15 turns before max_turns, commit what is finished and report partial.
An edit is needed outside emit_core_types.nika, its lowered twin and the test; rustc refuses every for<'call> form over AsyncFn (then report blocked with the lowered line and rustc’s message); an error in another agent’s file.
Not yours, never stage: every file git status shows modified or untracked at your start, 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 (scripts/commit.nika -- REPORT does it); commit locally after each step and never push: the driver runs the complete suite and pushes (.claude/agents/builder.md, Cheap checks only; owner, 2026-10-31).cargo build --profile fast -p nikaia, lower-std and its fixpoint when a tools/*.nika changed, cargo fmt, cargo clippy --all-targets -- -D warnings, scripts/pre-push-check.sh, the tests the brief names and the ones your change touches. No gate.nika.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: architect 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.Result: partial with what you ruled out, the probe, and the suspected file and function (.claude/agents/builder.md).target/fast/nikaia run scripts/commit.nika -- REPORT, which writes Pushed: local <sha> into it. 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/bugs/b11-1048-two-view-function-type.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