/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

_PATHS=$(python "${CLAUDE_PLUGIN_ROOT:-plugins/cc_develop}/bin/dev_shared_resolve.py" --foundry 2>/dev/null)  # timeout: 5000
_DEV_SHARED=$(echo "$_PATHS" | head -1)
_FOUNDRY_SHARED=$(echo "$_PATHS" | tail -1)
# 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`.

_DEV_SHARED=$(python "${CLAUDE_PLUGIN_ROOT:-plugins/cc_develop}/bin/dev_shared_resolve.py" 2>/dev/null)  # timeout: 5000
cat "$_DEV_SHARED/task-hygiene.md"

Project Detection

_DEV_SHARED=$(python "${CLAUDE_PLUGIN_ROOT:-plugins/cc_develop}/bin/dev_shared_resolve.py" 2>/dev/null)  # timeout: 5000
cat "$_DEV_SHARED/runner-detection.md"

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

**Language preflight gate**: after runner-detection.md, check project type:

# timeout: 5000
if [ ! -f "pyproject.toml" ] && [ ! -f "setup.py" ] && [ ! -f "setup.cfg" ]; then
    NON_PY=$(ls package.json Cargo.toml go.mod 2>/dev/null | head -1)
fi

If `NON_PY` non-empty: invoke `AskUserQuestion` — "Non-Python project detected (`$NON_PY` present, no pyproject.toml/setup.py). This toolchain assumes pytest. How to proceed?" · (a) **Abort** — use language-native toolchain · (b) **Continue** — I know what I'm doing (project has Python). On Abort: stop.

**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`.

_DEV_SHARED=$(python "${CLAUDE_PLUGIN_ROOT:-plugins/cc_develop}/bin/dev_shared_resolve.py" 2>/dev/null)  # timeout: 5000
cat "$_DEV_SHARED/preflight-helpers.md"

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

**Checkpoint init**: run `DEV_DIR=$(python "${CLAUDE_PLUGIN_ROOT:-plugins/cc_develop}/bin/dev_run_dir.py" 2>/dev/null) # timeout: 5000` to create `.developments/<TS>/` and capture 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.

# persist DEV_DIR for compaction recovery — bash state lost between Bash() calls  # timeout: 5000
export CSID="${CLAUDE_CODE_SESSION_ID:-$PPID}"
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. Pe