cf-sys-debug

# Systematic Debugging > **CLI Requirement:** OPTIONAL — Uses the memory MCP from `coding-friend-cli` for fast indexed search and storage. Without the CLI: falls back to grep over `docs/memory/` and direct file writes. Full functionality preserved, slower memory recall. See [CLI requirements](../../../docs/cli-requirements.md). ## Custom Guide Custom guide — auto-loaded below (if the raw command shows instead of its output, run it yourself): ```! bash "${PLUGIN_ROOT}/lib/load-custom-guide.sh" cf-sys-debug ``` If output is not empty, integrate returned sections: `## Before` → before first step, `## Rules` → apply throughout, `## After` → after final step. ## Core Constraint **Do not touch code until you can state the root cause in one sentence:** > "I believe the root cause is [X] because [evidence]." Name a specific file, function, and line. "A state management issue" is not testable. "Stale cache in `useUser` at `src/hooks/user.ts:42` because the dependency array is missing `userId`" is testable. If you cannot be that specific, you do not have a hypothesis yet. **Same symptom after a fix = hard stop.** Both a recurrence and "let me just try this" mean the hypothesis is unfinished. Re-read the execution path from scratch before touching code again. **After 3 failed hypotheses, stop.** Use the Handoff Format below to surface what was checked, ruled out, and unknown. Ask how to proceed. ## Rationalization Watch When these surface, stop and re-examine: | Thought ...