agent: builder model: opus max_turns: 80 budget_usd: 15 —
let mut text literal reassigned in an if and pushed as an owned variant field reaches rustc (E0308)Score: S=3 (a false acceptance: the checker passes, rustc refuses; found by the yaml lane, y4b), O=0.3 M, C=4 M (the text tier walk, like #943 at 417fc047), area bugs.
enum E { V(String), N }
fn main() {
let c = true
let mut held: Vec[E] = []
held.push(E::V(f"{1}"))
let mut why = "a"
if c { why = "b" }
held.push(E::V(why))
for e in held { match e { E::V(s) => println(s), E::N => println("n") } }
}Today: rustc Mismatched types at held.push(E::V(why)) (&str vs String). Expected 1 then b. The variant field is owned text (another push builds it with f"..."), so why must be owned where it goes in, or the push converts it.
crates/nikaia-std/src/tools/text_tiers.nika: the tier of a let literal and of its reassignments (417fc047, #943: a literal bound by a let is declared String); how a push into a variant whose field owns decides (#942, #969 in adfaf97a’s list). ADR-282 D12-D14 (docs/specification/adr/adr-282.md) govern which tier a text takes.if (let mut why = "a", why = "b", push) and with let why = "a" (no mut): if they run, the defect is the join over the if; say which in Body:.let mut text literal follows its uses through every assignment, the ones in an if/match arm included: a use that hands it to an owned field makes it owned at the let (or converts at the use, whichever ADR-282 D12-D14 prescribe; name the D in Body:).tests/compiler/tests/a_let_mut_literal_into_an_owned_variant.nika with .stdout: the probe, the same with match in place of if, and a struct field in place of the variant. Run against the unfixed compiler first; then the tests whose names hold tier, literal or let_mut.Only text_tiers.nika (and, if the tier is read there, the emit file that spells the let), their lowered files and lowered.rs, and the new test are yours; another file needed: stop, report partial with what and why.
The commit that finishes it says Fixes #1010.
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/bugs/b6-1010-let-mut-literal-owned-field.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