2ykwang/github-review-check-duplicate

GitHub Duplicate Issue Checker

Analyze an issue to determine if it is a duplicate and find related issues and PRs.

Use this skill when

• A new issue is filed and needs duplicate checking before triage
• Searching for existing issues or PRs related to a specific issue
• Deciding whether to close an issue as a duplicate

Do not use this skill when

• The user wants a general issue summary (use github-review-issue)
• The user wants a PR review (use github-review-pr)
• The user wants to create or edit issues

Instructions

Input

$ARGUMENTS is an issue number or GitHub URL.

• URL (e.g., https://github.com/owner/repo/issues/749): extract owner/repo, use --repo flag
• Number only: detect current repo via gh repo view --json nameWithOwner -q .nameWithOwner

Step 1: Fetch Issue Details

gh issue view $ARGUMENTS --json number,title,body,labels,author,createdAt,comments

• Extract key terms from title and body
• Check comments for ongoing discussion and referenced issues/PRs
• Classify issue type (bug report / feature request / question / other)
• Note error messages, stack traces, and specific file names

Step 2: Multi-Angle Search

A single search is insufficient. Use multiple strategies:

2-1. Keyword Search (at least 2-3 variations)

gh search issues "<original keywords>" --repo {owner/repo} --limit 20
gh search issues "<synonym keywords>" --repo {owner/repo} --limit 20
gh search issues "<error code or filename>" --repo {owner/repo} --limit 15

Examples:

• Original: "login fails" → Synonym: "authentication error", "sign in broken"
• Original: "500 error" → Related: "internal server error", "server crash"

2-2. PR Search

gh search prs "<keywords>" --repo {owner/repo} --limit 15

2-3. Label-Based Search (if labels exist)

gh issue list --label "<related label>" --state all --limit 20 --json number,title,state --repo {owner/repo}

2-4. Cross-Reference Check

gh api repos/{owner}/{repo}/issues/{issue-number}/timeline --jq '.[] | select(.event == "cross-referenced")'

Step 3: Analyze Candidates

For the top 5-10 similar issues from search results, fetch details:

gh issue view <number> --repo {owner/repo} --json number,title,body,state,comments

• Determine if similarity is superficial (title only) or substantive (same problem)
• Check if they share the same root cause
• Check if already resolved (closed + resolution comment)
• Look for related PRs mentioned in comments

Step 4: Duplicate Criteria

Mark as duplicate if any of the following apply:

| Criterion | Example | |-----------|---------| | Same bug/error | Same error message, same reproduction steps | | Same feature request | Different wording but identical desired functionality | | Same question | Asked differently but seeking the same answer | | Same root cause | Different symptoms but same underlying cause |

Mark as not duplicate if:

• Similar area but different specific problem
• Same feature, different perspective or scope
• Previous issue was resolved and this is a regression

Step 5: Output

Duplicate Found

Duplicate Found

Original: #123 - "title" (URL)
State: Open / Closed
Evidence:
  - Same error message "XXX" reported
  - Identical reproduction steps (do A then B)
  - Same component/file involved

Recommended Action:
  - Add duplicate label
  - Consider closing this issue

Related Items Found (not duplicate but related)

Related Items Found

Related Issues:
  - #456 - "title" (URL) — different bug in the same module
  - #789 - "title" (URL) — similar feature request, different scope

Related PRs:
  - #101 - "title" (URL) — Open, fix in progress for this issue
  - #102 - "title" (URL) — Merged, relevant prior fix

No Duplicates Found

No Duplicates Found

Search Summary:
  - Issues searched: N
  - Issues examined in detail: M
  - Assessment: appears to be a new issue

Suggested labels: bug / feature-request / question / etc.