Formulate a fix approach for a confirmed Unop issue, apply it, run tiger, commit, and push. Read full context from a shared file and append a ## Fix N section with the approach and changes.

This skill runs autonomously, without asking for approval. Any human gates belong to the calling workflow, not here. It reports a summary at the end.

Concepts

GitHub repo: ProZeratul/CrusaderKings3UnofficialPatch. Use the gh CLI for all GitHub operations.
Issue: A bug report (or occasionally an enhancement request) opened against the Unop repo.
Shared file: tmp/issue-<N>.md — the handover document. Other skills may create it with the ## Analysis section and append ## Review N sections. This skill reads both and appends ## Fix N.

Context

Commands should be executed in the current working tree (the Unop repo root, or the worktree the session was launched in).

Arguments

Issue number (position $0, required): The GitHub issue number to fix (e.g. 419).
Identity (position $1): the role this skill posts as, defaults to fixer.

Guidelines

Read the project's CLAUDE.md first.
Identify yourself. Post as <identity>): begin each comment's first line with **<identity>:**. A comment containing @<identity> is addressed to you.
Read the shared file in full before formulating a fix — the ## Analysis section and every prior ## Fix N and ## Review N.
Read the relevant parts of the actual Unop and vanilla files before formulating the fix — don't rely on the investigation summary alone.
Decide the fix yourself. Trust the shared file's Findings and file-verified facts, but treat any Fix directions recorded there as one unverified hypothesis, not a spec. Re-derive the approach from the facts and choose the altitude.
Don't hand-classify tiger warnings. When make tiger reports new warnings, invoke the tiger skill to fix them properly.
Consult examples.md for relevant past investigations when a situation it covers comes up.

Workflow

1. Load Context

Read the shared file for the investigation findings, classification, and any prior fix/review cycles.

Re-fix due to review. If a ## Review N section is present, read the most recent one and treat its High and Medium findings as the work list for this attempt — every one must be addressed before you consider the fix ready. Low findings are optional. Earlier ## Fix N sections show what was already tried.

Re-fix due to PR feedback. If the fix has a linked PR and there is feedback after your last **<identity>:** comment (especially any addressing @<identity>), read its conversation and review comments — gh pr view <PR> --comments, plus inline comments via gh api repos/ProZeratul/CrusaderKings3UnofficialPatch/pulls/<PR>/comments. Take into account any feedback from the maintainers but vet each against the code; if you disagree, say so in the ## Fix N rather than silently complying.

Re-read the relevant Unop and vanilla files to refresh the context before formulating the fix.

2. Formulate the Fix Approach

Work out how to fix the bug before writing any code.

Look for the simpler fix first. Is there an existing trigger, variable, flag, or guard that already encodes the state? Avoid new state and new files unless the existing surface really can't express the fix. See examples.md (#420).
Find the right altitude. Before patching individual items, ask whether one higher-level guard subsumes them. When the bug spans members of a group, fixing the group is usually simpler and more complete; if an analogous system already handles the condition, mirror its mechanism. See examples.md (#498).
Enumerate the pattern class, including sibling systems. Identify the category (object group of family, analogous systems) and check every member — in other files too — for the same bug; fix all buggy ones in the same PR. See examples.md (#498).
Articulate the intent of any guard you propose to loosen. State in one sentence why the original code added it — reading the whole feature for intent, including its localization and effects, not just the guard. A narrow predicate may be a proxy for a real condition; target that condition rather than widening the proxy. See examples.md (#440, #501).
Verify against the other guards in the same block. Before removing or loosening a guard, simulate the post-change state against all other guards in the same is_shown / is_valid / can_create. If another guard still blocks the reporter's case, the fix doesn't work. See examples.md (#440).
Check all siblings, not just the ones with the matching pattern. When a fix applies a guard to some items in a group, read every sibling item's conditions to determine whether it has the same exposure. A sibling whose conditions look unrelated may still be satisfiable by the invalid subject through a different path.
Find all call sites of the buggy code path. Grep the symbol you're about to guard. Vanilla often runs the same logic in 2-3 places; missing a duplicate leaves the bug unfixed. See examples.md (#213).
Evaluate suggested fixes critically. Both the reporter's diagnosis and any Fix directions in the shared file are candidates, not defaults — re-derive the approach from the verified facts. Watch for fixes that destroy state other systems still depend on. See examples.md (#213, #498).
Name the load-bearing assumption. State the single behavioral assumption the fix rests on and corroborate it from files (a working precedent, a .info/log line); if it can't be confirmed, flag it for in-game testing. See examples.md (#498).
On a re-fix, make sure the new approach resolves the review findings rather than working around them.

Paradox Script Gotchas:

custom_description is a tooltip wrapper, not a condition. custom_description = { text = X; <trigger> } evaluates <trigger> and labels failures with X's loc — the text = line is not a separate condition.

3. Apply the Fix

Following the project CLAUDE.md "General", "Style", and "Opening PRs" guidelines:

Be on a fix branch. If you're on the default branch (main), create one from a clean tree; otherwise you're already on the fix branch — use it.

# First attempt, only when on main. Working tree should be clean apart from .claude/; if not, stop.
git status --porcelain | grep -v '^.. \.claude/'
git checkout main && git pull --ff-only
git checkout -b <git-user>-fix-<short-slug>   # from the issue title, no issue number

Apply the fix. Minimal change; #Unop comment on the first changed line; comment out rather than delete unneeded vanilla code. When enclosing existing code in a scope, indent it properly. New vanilla files should be added without modifications in a separate commit.
Validate: run make tiger and ensure no new errors or warnings.
- If new errors appear in newly-added vanilla files, fix or ignore them in the same PR.
- **invoke the tiger skill to handle tiger error reports.
Commit fix files scoped by path. Stage explicitly (git add -- <path>, never git add -A) and commit with a pathspec: git commit -m "<summary>" -- <path...>. Before committing, run git diff --cached --name-only and confirm only the fix files are listed. Commit message: short imperative summary.
Open or update the PR:
- First fix attempt: open a draft PR whose description contains a Fixes #<N> line and a concise description of the fix prefixed with **<identity>:**. The Fixes #<N> line auto-links the issue, which already contains the analysis comment and labels. This description is your first-fix comment — don't also post a separate PR comment.
```
gh pr create --draft --title "<title>" --body "$(cat <<'EOF'
Fixes #<N>

**<identity>:** <short description of the fix>
EOF
)"
```
- Re-fix attempt: push to the existing branch — the PR updates automatically. Then post a concise **<identity>:** PR comment explaining what changed (gh pr comment <PR>, resolving <PR> with gh pr view --json number -q .number on the checked-out branch); if the re-fix addressed PR feedback, reply to those comments directly.

4. Append to the Shared File

Append a ## Fix N section to the shared file (N = 1 for the first attempt, 2 for the second, etc.):

## Fix N

**Approach:** <one-sentence description>

**Addresses review:** <which Review findings this resolves; omit on the first attempt>

**Files changed:**
- `<path>` — <one-line note>

**Key assumption:** <the single behavioral assumption the fix depends on, and its corroboration — or "test in-game" if unconfirmed>

**Commit:** <commit message>

**PR:** <PR URL> | existing PR updated

5. Report Summary

When done, report to the user:

Approach applied and why; on a re-fix, which review findings it resolved.
Files changed, commit, PR link.
Ask the user to manually verify the fix in-game and run in observer mode to check error.log for errors related to the fix.

Reference

Examples

examples.md contains past investigations, one section per issue. Read the relevant section when its situation comes up.

Usage Examples

/unop-fix-issue 419