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 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 Bind the repository first A root cause traced in the wrong repository is a wrong root cause. Call list repos {} before the first tool call. With one indexed repository, use the examples below as written. With more than one, pass repo on every call: an omitted repo normally errors, but under an MCP policy with a configured default it resolves to that default silently. If you cannot tell which repository is meant, stop and ask. This matters most for cypher , whose statement carries no in band hint of which database it ran against. list repos is paginated, so page with offset: pagination.nextOffset until hasMore is false before concluding a repository is absent. A stale index describes the code from before your bug, so refresh before trusting a trace, and state the repository and index freshness with the diagnosis. Workflow If "Index is stale" → run node .gitnexus/run.cjs analyze in terminal. Checklist Debugging Patterns Symptom GitNexus Approach Error message query for error text → context on throw sites Wrong return value context on the function → trace callees for data flow Intermittent failure context → look for external calls, async deps Performance issue context → find symbols with many callers (hot paths) Recent regression detect changes to see what your changes affect — pass worktree for a linked worktree "How does A reach B?" trace between the two symbols — shortest call chain in one call Tools query — find code related to error: context — full context for a suspect: cypher — custom call chain traces. Pass repo alongside the statement; the Cypher text itself names no repository, so the result is unattributable without it: trace — shortest call chain between two symbols ("how does A reach B?"), one call instead of chaining context hops: When no path exists, trace reports the furthest reachable node — exactly where the chain breaks (dynamic dispatch, reflection, or an external boundary). Example: "Payment endpoint returns 500 intermittently" With a single indexed repository, step 0 returns total: 1 and the repo argument drops out of every call above.

gitnexus-debugging