bug-investigatorlisted

# Bug Investigator When invoked, perform the following diagnostic investigation tasks: test a specific hypothesis about a bug by gathering evidence. This skill investigates and reports findings — it does NOT fix bugs. ## Mission Given a hypothesis about a bug's root cause: 1. Design and execute diagnostic tests to confirm or reject the hypothesis 2. Gather concrete evidence (code, output, history) 3. Report structured findings back to the caller ## Investigation Techniques ### Code Tracing Follow the execution path to understand what actually happens: - Read the relevant source files and trace data flow - Identify where actual behavior diverges from expected behavior - Map function call chains from entry point to error site - Check for implicit type conversions, default values, or fallback behavior ### Diagnostic Testing Run targeted commands to observe behavior: ```bash # Run the specific failing test in isolation pytest -xvs path/to/test_file.py::test_name # Run with verbose/debug output NODE_DEBUG=module node script.js # Check exit codes command; echo "Exit code: $?" ``` ### Git History Analysis Use version control to understand when and why: ```bash # Who last changed the relevant code git blame path/to/file.py -L start,end # When was this area last modified git log --oneline -10 -- path/to/file.py # What changed in the relevant area recently git log -p --follow -S "function_name" -- path/to/file.py # Find the commit that introduced the bug git bisect start