SKILL.md
Code Debugging
Systematically debug experiment code with structured error categorization and fix strategies.
Input
$0— Error message, stderr output, or code file with issues
$1— Optional: the code that produced the error
References
- Debug patterns and state machine:
~/.claude/skills/code-debugging/references/debug-patterns.md
Workflow
Step 1: Categorize the Error
Category
Examples
Severity
SyntaxError
Invalid syntax, indentation
Low
ImportError
Missing module, wrong name
Low
RuntimeError
Division by zero, shape mismatch
Medium
TimeoutError
Infinite loop, too slow
Medium
OutputError
Missing files, wrong format
Medium
LogicError
Wrong results, 0% accuracy
High
Step 2: Analyze Root Cause
- Read the error traceback (last 1500 chars if truncated)
- Identify the exact line and variable causing the error
- Check for common patterns:
- Device mismatch (CPU vs GPU tensors)
- Shape mismatch in matrix operations
- Missing data normalization
- Off-by-one errors in indexing
- Incorrect loss function for task type
Step 3: Apply Fix Strategy
For syntax/import errors: Direct fix, single attempt
For runtime errors: Fix and rerun, up to 4 retries
For logic errors: Reflect on approach, consider alternative methods
For timeout: Reduce dataset size, optimize bottleneck, add early stopping
Step 4: Reflect and Prevent
After fixing:
- Explain why the error occurred
- Identify which lines caused it
- Describe the fix line-by-line
- Note patterns to avoid in future code
Fix Strategy State Machine
Stage 0 (first attempt) → repost code as fresh
Stage 1 (second attempt) → repost or leave depending on severity
Stage 2 (third attempt) → regenerate from scratch if still failingRules
- Prefer minimal targeted edits over full rewrites
- Maximum 4-5 fix attempts before changing approach
- Always truncate long error outputs to last 1500 characters
- After fixing, verify the fix doesn't introduce new errors
- Keep error history to avoid repeating the same mistakes
- If 0% accuracy: check accuracy calculation first, then check data pipeline
Related Skills
- Upstream: experiment-code
- See also: paper-to-code, data-analysis