Principle Fix Root Causes

Apply when debugging. Trace each symptom to its root cause and fix it there; reproduce first, ask why until you reach it, resist nil-check guards that silence crashes.

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Fix Root Causes

When debugging, do not paper over symptoms. Trace every problem to its root cause and fix it there.

Why: Symptom fixes accumulate. Each workaround makes the system harder to reason about without fixing the bug. Root-cause fixes are slower upfront but reduce total debugging time.

Pattern:

  • Reproduce first (if you can't reproduce it, you can't verify your fix)
  • Ask "why" until you hit the root cause
  • Resist the urge to add guards (adding a nil check to silence a crash is a symptom fix)
  • If a workaround needs a paragraph-long comment to justify it, the code is wrong (fix the code, not the comment)
  • Check for the pattern, not just the instance (grep for the same pattern, fix all instances)
  • When stuck, instrument. Don't guess (add logging, read the actual error)

Restart bugs: suspect state before code

Code doesn't change between runs. State does. When something "fails after restart," suspect stale persistent state first: config files, caches, lock files, serialized state. If clearing a state file restores behavior, prioritize state validation as the fix.

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