gitnexus-debugging - SKILL.md Agent Skill

name: gitnexus-debugging description: "Use when the user is debugging a bug, tracing an error, or asking why something fails. Examples: "Why is X failing?", "Where does this error come from?", "Trace this bug""

Debugging with GitNexus

IMPORTANT — How to use GitNexus: GitNexus is a standalone CLI tool. Run it directly via gitnexus <command> in the Bash tool. Do NOT use mcpl call gitnexus ... or npx gitnexus ... — gitnexus is installed globally and invoked by name.

Multi-repo note: Always pass --repo <name> to every command that operates on a specific repo to avoid "multiple repositories" errors.

When to Use

"Why is this function failing?"
"Trace where this error comes from"
"Who calls this method?"
"This endpoint returns 500"
Investigating bugs, errors, or unexpected behavior

Workflow

1. gitnexus query "<error or symptom>" --repo <name>      → Find related execution flows
2. gitnexus context "<suspect>" --repo <name>              → See callers/callees/processes
3. gitnexus cypher 'MATCH path...' --repo <name>           → Custom traces if needed
4. Read source files to confirm root cause

If "Index is stale" → run gitnexus analyze in terminal.

Checklist

- [ ] Understand the symptom (error message, unexpected behavior)
- [ ] gitnexus query for error text or related code
- [ ] Identify the suspect function from returned processes
- [ ] gitnexus context to see callers and callees
- [ ] gitnexus cypher for custom call chain traces if needed
- [ ] Read source files to confirm root cause

Debugging Patterns

Symptom	GitNexus Approach
Error message	`gitnexus query` for error text → `gitnexus context` on throw sites
Wrong return value	`gitnexus context` on the function → trace callees for data flow
Intermittent failure	`gitnexus context` → look for external calls, async deps
Performance issue	`gitnexus context` → find symbols with many callers (hot paths)
Recent regression	`gitnexus detect-changes` to see what your changes affect

CLI Commands Reference

All commands are run directly via the Bash tool. Do not use mcpl or npx.

Command	What it gives you	Example
`gitnexus query "<concept>" --repo <name>`	Execution flows related to a concept	`gitnexus query "payment validation error" --repo <name>`
`gitnexus context "<symbol>" --repo <name>`	360-degree symbol view — callers, callees, processes	`gitnexus context "validatePayment" --repo <name>`
`gitnexus cypher "<query>" --repo <name>`	Raw graph queries for custom call chain traces	`gitnexus cypher "MATCH ..." --repo <name>`
`gitnexus detect-changes --repo <name>`	What your current changes affect	`gitnexus detect-changes --repo <name>`

Example: "Payment endpoint returns 500 intermittently"

1. gitnexus query "payment error handling" --repo my-app
   → Processes: CheckoutFlow, ErrorHandling
   → Symbols: validatePayment, handlePaymentError

2. gitnexus context "validatePayment" --repo my-app
   → Outgoing calls: verifyCard, fetchRates (external API!)

3. Root cause: fetchRates calls external API without proper timeout