root-cause-debug

After this, the AI stops guess-and-check thrashing and runs a four-phase root-cause process before changing any code — typical debug time drops from hours to minutes.

For developers stuck in the "fix one bug, create three more" loop.

Before: "The build broke after I ran the migration"

[Tries fix 1: reverts a constraint. Still broken.
Tries fix 2: adds an index. Different error appears.
Tries fix 3: changes the migration order. Original error returns.
Twenty minutes lost. Three new bugs in different places.]

After: "The build broke after I ran the migration"

Phase 1 — Reproduce: confirmed broken on clean checkout
Phase 2 — Isolate: narrowed to migration 0042
Phase 3 — Hypothesise: "FK constraint references a column 0041 renamed"
Phase 4 — Verify: reads both migrations, confirms

"Root cause: 0042 references user_id, but 0041 renamed it to account_id. Fix: change line 14 of 0042 from user_id to account_id. One change, one rebuild, verified."

Use when

• a test or build just broke
• a previous fix didn't stick
• under time pressure (especially under time pressure)

Three ways to use this

1. Paste it (any AI, 30 seconds, no install)
   Open the .md file, copy contents, paste into Claude / ChatGPT / Cursor / Perplexity with: "Read this and apply it whenever the task it describes comes up in our conversation." Done.
2. Install it (Claude Code / Cursor users)
   Drop the unzipped folder into ~/.claude/skills/ (Claude Code), .cursor/skills/ (Cursor), or your IDE's equivalent. Auto-loads next session.
3. New to AI assistants? Get Claude free at claude.ai, then use Option 1.

€7