Stabilize null path crash
Medium Debugging arena: stack traces, nullability, and guard placement
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Missing prerequisites: debugging-easy-null-path
A profile page crashes only for users who have never uploaded an avatar. You are working inside a debugging war room, and the arena only clears when the result is safe, deterministic, and explainable.
Learn to apply stack traces, nullability, and guard placement in a debugging war room while explaining the invariant, safety constraints, and hidden edge cases.
- Demonstrates stack traces, nullability, and guard placement
- Handles the visible sample and hidden edge cases
- Keeps output deterministic and explainable
- Avoids unsafe dynamic execution
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Genie Mentor Core
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