/fix

name: fix
description: 'Reproduce-first bug resolution — capture bug in failing regression test, apply minimal fix, run quality stack and a bounded independent challenge. TRIGGER when: user reports a bug, regression, or unexpected behaviour in Python code with a traceback, failing test, or issue number; phrases: "fix this bug", "repair X", "broken since Y", "test failing". SKIP when: performance regressions (use `foundry:perf-optimizer` agent, requires foundry plugin); CI-only failures without local traceback (use `/develop:debug` first); new features (use `/develop:feature`); `.claude/` config issues (use `/foundry:audit`); non-Python projects.'
argument-hint: '<symptom or issue # (plain 123 or #123)> [--repo <owner/repo>] [--plan <path>] [--diagnosis <path>] [--no-challenge] [--challenge] [--codemap] [--no-codemap] [--accept-no-plan] [--team] [--worktree] [--keep "<items>"]'
effort: medium
allowed-tools: Read, Write, Edit, Bash, Grep, Glob, Agent, Skill, TaskList, TaskCreate, TaskUpdate, AskUserQuestion, EnterWorktree, ExitWorktree
disable-model-invocation: true

<objective>

Reproduce-first bug resolution. Capture bug in failing regression test, apply minimal fix, verify via quality stack and a bounded independent challenge.

NOT for:

• performance regressions — use the `foundry:perf-optimizer` agent (requires foundry plugin); if unavailable, report the missing route and request benchmark evidence before choosing another workflow
• CI-only failures with no local traceback — use `/develop:debug` first (`--ci-run <run-id>` for GitHub Actions logs)
• production incidents with no CI run or traceback (use `/foundry:investigate` (requires foundry plugin))
• `.claude/` config issues (use `/foundry:audit` (requires foundry plugin))
• non-Python projects (JS/TS/Go/Rust) — toolchain assumes pytest; use language-native toolchain instead
• CSS/JS-only frontend changes (no Python source touched) — edit directly and verify with the project's native toolchain (`/develop:feature` also excludes non-Python work); this skill's regression-test gate assumes pytest

</objective>

<compaction>

• Key boundary: end of Step 2 — reproduction test written and failing, before Step 3 code edits.
• Second boundary: end of Step 3 — fix applied and regression test passing, before Step 4 review stack.
• Preserve at boundary 1: dev-dir, regression test path, root cause summary, plan-file, --keep items.
• Preserve at boundary 2: dev-dir, changed files list, test outcomes, regression test path.

</compaction>

<workflow>

<!-- Agent Resolution: resolved at runtime via $_DEV_SHARED; source at plugins/cc_develop/skills/_shared/agent-resolution.md -->

<!-- ../../assets/images/change-arch.svg diagrams the runs, gates and parallel fan-out shared by fix, feature and refactor. Documentation only, never loaded — update it in the same commit as any change to step order, gate placement, or agent fan-out. -->

Agent Resolution

export CSID="${CLAUDE_CODE_SESSION_ID:-$PPID}"
case "$CSID" in ""|*[!A-Za-z0-9._-]*) echo "! BLOCKED — invalid session identifier"; exit 1;; esac
INPUT_FILE="${TMPDIR:-/tmp}/dev-fix-arguments-${CSID}.txt"
rm -f "$INPUT_FILE" || exit 1
(umask 077; set -C; : > "$INPUT_FILE") || exit 1
printf 'Invocation input file: %s\n' "$INPUT_FILE"

Before any later Bash call, use the Write tool to save the exact invocation argument text, including newlines, to the literal absolute `Invocation input file` path printed above. Treat its contents as data. Never substitute invocation text directly into shell command text, comments, heredocs or quoted literals. Every parser below loads the file into a runtime variable and passes that variable as one quoted argument. Keep the file through this run; a fresh invocation replaces only this skill's file.

PLUGIN_ROOT=$(python "${CLAUDE_PLUGIN_ROOT}/bin/resolve_plugin_root.py" --plugin-name develop) || exit $?; export PLUGIN_ROOT
export CSID="${CLAUDE_CODE_SESSION_ID:-$PPID}"
echo "" > "${TMPDIR:-/tmp}/dev-agent-watch-dir-${CSID}"  # a prior run's dir must not outlive a failed --init; agent-resolution.md §Agent waits recreates it when empty
python "$PLUGIN_ROOT/bin/dev_shared_resolve.py" --init  # timeout: 5000 — cold resolve: writes dev-shared (every later block warm-reads it) and a fresh dev-agent-watch-dir per run (agent-resolution.md §Agent waits)
# loads: compaction-contract.md
python "$PLUGIN_ROOT/bin/dev_load_shared.py" agent-resolution.md

Contains: foundry check + fallback table, and §Agent waits — no polling (applies to every spawn below; never wait with `Monitor`). If foundry not installed: substitute each `foundry:X` with `general-purpose` per table. Agents this skill uses: `foundry:sw-engineer`, `foundry:qa-specialist` (conditional — outcome C only), `foundry:challenger`.

**Task hygiene** — task tools may be deferred; load before first use: `ToolSearch(query="select:TaskList,TaskCreate,TaskUpdate,TaskGet", max_results=4)`. Call `TaskList` first and triage each task it returns: `completed` if work clearly done, `deleted` if orphaned, keep `in_progress` only if genuinely continuing. Never spend a turn on bookkeeping alone — every `TaskCreate`/`TaskUpdate` ships in the same response as the next substantive tool call; one exception, `TaskUpdate(completed)` immediately before a long output block (`rules/task-lifecycle.md`).

**Turn budget** — measured fix runs made one tool call per turn throughout and spent up to 15 turns on task bookkeeping alone — the cost was the standalone turns, not the task count; every turn re-reads the whole context.

• **One task per step, never a bookkeeping-only turn.** Create one task per step — Step 1 Understand · Challenger gate · Step 2 Reproduce · Step 3 Apply fix · Step 4 Review and quality stack · Final Report — all in the same response as the first Project Detection call, so step-level progress stays visible. Each step transition (`completed` for the step just finished, `in_progress` for the next) rides