investigate

name	investigate
description	Deep investigation of GitHub issues with root cause analysis and proposed solutions. Use when asked to investigate, analyze, or dig into an issue.
model	opus
context	fork
agent	investigator
effort	high

Investigate GitHub Issue

Investigate the following GitHub issue: $ARGUMENTS

Instructions

Phase 1: Fetch Issue Details

1. Parse the input:
   • DX-123 or linear.app URL → Linear ticket
   • #123, bare number, or github.com URL → GitHub issue
2. Fetch the ticket:
   • GitHub: gh issue view <number> --json title,body,labels,comments,author,createdAt,state
   • Linear: bash .agents/skills/triage/scripts/linear-fetch.sh issue DX-123
3. Extract: error messages, stack traces, reproduction steps, environment details

Phase 2: Identify Affected Package(s)

1. Check issue labels for pkg:* tags
2. Search title/body for package names or import statements
3. Check stack traces for file paths
4. Package folders are in packages/ — use labels and keywords to identify

Phase 3: Deep Analysis

1. Search for error messages and referenced functions in the codebase
2. Trace the execution path from entry point to the reported behavior
3. Check recent commits: git log --oneline -20 -- packages/<name>
4. Search similar issues: gh issue list --search "<keywords>" --state all --limit 10

Phase 4: Root Cause Analysis

Determine category: bug in logic, API change, type mismatch, missing validation, race condition, environment issue, configuration, or documentation gap.

Phase 5: Propose Solutions

For each root cause: the fix (file paths + line numbers), test coverage needed, verification commands.

Output

1. Extract identifier from arguments (issue 424 → 424, ticket DX-296 → DX-296, text → slugified)
2. mkdir -p claude-output
3. Write to claude-output/investigate-<identifier>.md
4. Confirm to user: "Investigation written to claude-output/investigate-<identifier>.md"

Output Structure

# Investigation: Issue #<number>

**Title:** | **URL:** | **Created:** | **State:** | **Author:**

## Summary
## Affected Package(s) (table: Package, Confidence, Evidence)
## Issue Details (Reported Behavior, Expected Behavior, Environment, Reproduction Steps)
## Code Analysis (Relevant Files table, Execution Flow, Code snippets)
## Root Cause (Category, Explanation, Evidence)
## Proposed Solutions (Changes table, Code before/after, Tests to add, Verification)
## Similar Issues
## Notes / Risks
## Next Steps