Debug

Debug

Systematically debug the problem described in $ARGUMENTS. Do not guess. Do not fix without reproducing first.

Step 1: Understand and categorize the problem

Parse $ARGUMENTS for:

• What is the observed behavior?
• What is the expected behavior?
• Is there an error message or stack trace?
• When did this start? After what change?

If critical information is missing, ask for it before proceeding.

Categorize the issue type — the investigation strategy depends on this:

• Runtime error — exception, crash, panic, unhandled promise rejection
• Logic error — wrong output, incorrect calculation, unexpected state
• Performance — slow response, high CPU/memory, timeout
• Intermittent — flaky, race condition, timing-dependent
• Environment-specific — works locally, fails in CI/staging/production
• Build/type error — compilation failure, type mismatch, import error

Step 2: Investigate — spawn the debugger agent

Spawn the debugger agent to investigate in isolation. This keeps debug artifacts out of the main context and uses the agent's systematic root cause methodology.

Pass the following as the agent task:

Bug report: <observed behavior from Step 1>
Expected behavior: <expected behavior from Step 1>
Issue category: <category from Step 1>
Error/stack trace (if any): <paste here>
Reproduce with: <failing test command or steps>

The debugger agent will return:

• Root cause with evidence and location (file:function:line)
• Proposed minimal fix
• Class of bug — other locations in the codebase with the same assumption
• Detection gap — what would have caught this sooner

If the agent cannot reproduce the issue: do not guess. Surface the agent's findings to the user and ask for more context (environment details, additional logs, or a more specific reproduction case).

Step 3: Apply the fix

Review the root cause and proposed fix from the debugger agent.

Make the minimal change that fixes the root cause — not the symptom:

• Do not fix multiple things in one commit
• Do not refactor unrelated code while fixing
• Add a comment if the fix is non-obvious: // Fix: <why this is necessary>

Also check the "class of bug" output — if other locations share the same flawed assumption, fix those too (or note them as follow-up).

Step 4: Write a regression test — spawn the qa agent

Spawn the qa agent to write the regression test. Pass:

Bug fixed: <one-sentence description of the root cause>
Fix location: <file:line of the fix>
Reproduce with: <the reproduction case from Step 2>

The test must:

• Fail with the bug present (verify this before the fix)
• Pass after the fix
• Document why it exists (describe the bug it prevents in the test name or comment)

A fix without a regression test is incomplete.

Step 5: Verify

# Run the regression test to confirm it passes
# Run tests covering the affected area
# Run the full suite to check for regressions
# Re-run the original reproduction case — confirm the issue is gone

Step 6: Output

Summarize:

• Root cause: what was actually wrong and why
• Fix: what was changed and the reasoning
• Regression test: what test was added and what it covers
• Verification: test output confirming the fix
• Follow-up: class-of-bug locations to check, tech debt, missing detection gaps