agent: builder model: opus max_turns: 90 budget_usd: 18 effort: medium —
let mut stays a view; #1143 a temporary handed to a parameter that is returnedBlocks: s2-bounds-report (the bounds_report move, #125)
Score: two defects, specified behaviour, rustc rejects the lowered code and its error reaches the user. Both found by the probes for s2 (supervisor, 2026-11-01).
Facts: Where things live, Traps already met, Commands
The probes are verbatim in #1142 and #1143 (run them with target/fast/nikaia run):
let mut sites = walk.sites (last use of walk), then sites.sort_by_key(fn(s) { s.line }) or sites.push(..): a warning “does not need to be mutable” and rustc’s “Cannot borrow *sites as mutable, as it is behind a & reference”. Expected 1. walk.sites.sort_by_key(..) in place works.pad_left(site.line.to_string(), 4) inside for site in sites, pad_left(text: String, width: i64) -> String returning text on one path: rustc’s “Temporary value dropped while borrowed”. Expected [ 7]. pad_left(f"{site.line}", 4) works.let mut is owned (moved at the owner’s last use, else what the existing rules say for a non-copy field; read the borrow/ownership ADRs the lowering cites and name the one you follow). Test tests/compiler/field_moved_into_mut.nika + .stdout (sort and push). Commit Fixes #1142.tests/compiler/temp_arg_returned.nika + .stdout. Commit Fixes #1143.
Run the tests your change touches (nikaia test on the new tests, the --test it filters of the files you change); lower-std and its fixpoint if a tools/*.nika changed..claude/agents/builder.md and docs/builder-facts.md first. Commit locally with target/fast/nikaia run scripts/commit.nika -- REPORT; the driver pushes.CHANGELOG.md, badges and NK codes are the supervisor’s.Result: partial with what you ruled out and the suspected file and function./home/user/Nikaia/docs/briefs/bugs/b35-1142-1143-owned-field-and-temp-arg.md.report.md)Fields of docs/supervisor.md, Briefs and reports. Final answer, one line: done <sha>, report <path> (or BLOCKED: ...).