/fix

name: fix
description: 'Reproduce-first bug resolution — capture bug in failing regression test, apply minimal fix, run quality stack and review loop. 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: 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] [--semble] [--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 review loop.

NOT for:

• CI-only failures with no local traceback — use `/develop:debug` first (`--ci-run <run-id>` for GitHub Actions logs)
• production incidents without any 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) — use `/develop:feature` for new frontend work or direct editing for surgical CSS/JS fixes; 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 -->

Agent Resolution

export CSID="${CLAUDE_CODE_SESSION_ID:-$PPID}"
_DEV_SHARED=$(python "${CLAUDE_PLUGIN_ROOT:-plugins/cc_develop}/bin/dev_shared_resolve.py" 2>/dev/null)  # timeout: 5000
[ -z "$_DEV_SHARED" ] && _DEV_SHARED="plugins/cc_develop/skills/_shared"
echo "$_DEV_SHARED" > "${TMPDIR:-/tmp}/dev-shared-${CSID}"  # cold resolve — every later block warm-reads this
# loads: compaction-contract.md
cat "$_DEV_SHARED/agent-resolution.md"

Contains: foundry check + fallback table. 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`.

export CSID="${CLAUDE_CODE_SESSION_ID:-$PPID}"
IFS= read -r _DEV_SHARED < "${TMPDIR:-/tmp}/dev-shared-${CSID}" 2>/dev/null || _DEV_SHARED=""  # timeout: 5000
[ -z "$_DEV_SHARED" ] && _DEV_SHARED="plugins/cc_develop/skills/_shared"
cat "$_DEV_SHARED/task-hygiene.md"

Project Detection

export CSID="${CLAUDE_CODE_SESSION_ID:-$PPID}"
IFS= read -r _DEV_SHARED < "${TMPDIR:-/tmp}/dev-shared-${CSID}" 2>/dev/null || _DEV_SHARED=""  # timeout: 5000
[ -z "$_DEV_SHARED" ] && _DEV_SHARED="plugins/cc_develop/skills/_shared"
cat "$_DEV_SHARED/runner-detection.md"

Sets `$TEST_CMD` (full suite) and `$PYTEST_CMD` (pytest flags). Run at skill start.

**Language preflight gate**: apply §Language preflight gate from `runner-detection.md` (loaded above) — sets `NON_PY` and runs the abort/continue question.

**Optional `--plan <path>`**: if `$ARGUMENTS` contains `--plan <path>` (at any position), read plan file first. Extract `Affected files`, `Risks`, `Suggested approach` — use to populate Step 1 analysis instead of cold codebase exploration. Skip agent feasibility re-check (already done in `/develop:plan`). Store plan path as `PLAN_FILE`.

export CSID="${CLAUDE_CODE_SESSION_ID:-$PPID}"
IFS= read -r _DEV_SHARED < "${TMPDIR:-/tmp}/dev-shared-${CSID}" 2>/dev/null || _DEV_SHARED=""  # timeout: 5000
[ -z "$_DEV_SHARED" ] && _DEV_SHARED="plugins/cc_develop/skills/_shared"
cat "$_DEV_SHARED/preflight-helpers.md"

Execute --plan path extraction; sets `$PLAN_FILE`.

**Checkpoint init**: creates `.developments/<TS>/` and captures path. Write `checkpoint.md` inside `$DEV_DIR`. After each major step (1, 2, 3, 4), append `step: N — completed` to `$DEV_DIR/checkpoint.md`. On skill start, check for existing `.developments/*/checkpoint.md` — offer resume from last completed step if found.

# timeout: 5000
export CSID="${CLAUDE_CODE_SESSION_ID:-$PPID}"
DEV_DIR=$(python "${CLAUDE_PLUGIN_ROOT:-plugins/cc_develop}/bin/dev_run_dir.py" 2>/dev/null)
echo "$DEV_DIR" > "${TMPDIR:-/tmp}/dev-fix-dev-dir-${CSID}"

Fix Mode

**Optional `--diagnosis <path>`**: if provided (from preceding `/develop:debug` session), read diagnosis file first. Skip Step 1 codebase analysis — root cause, suspect files, and evidence pre-populated from diagnosis file. Challenger gate still applies: proceed from pre-populated root cause through challenger gate, then to Step 2. Do NOT skip challenger gate — it reviews fix approach, not just root cause discovery.

DIAG_FILE=$(python "${CLAUDE_PLUGIN_ROOT:-plugins/cc_develop}/bin/diagnosis_parse.py" "$ARGUMENTS" 2>&1) || { echo "$DIAG_FILE"; exit 1; }  # timeout: 5000

Diagnosis file format: see `/develop:debug` Final Report section for canonical field definitions (Root Cause, Suspect Files, Evidence).

Flag parsing

Parse flags into actual shell variables (not prose) so downstream blocks see correct values. Persist to temp files for cross-block acces