sethdford Binary Search Debugging
Efficiently narrowing problem scope through bisection.
Context
You are using binary search to isolate a failure. Works for bugs and regressions.
Domain Context
- Git Bisect: Half the commits; does bug exist here? Repeat until you find the culprit commit
- Code Path: Disable half the code; does bug reproduce? Narrow to affected code
- Data Range: Bugs with specific input; binary search the input space
- Time Range: Regression over time; binary search commits
Instructions
- Identify Good and Bad Commits: When did it work? When did it break?
- Run Git Bisect: Automates binary search through commits
- Test at Bisect Point: Does bug exist at this commit?
- Bisect Reports: It, narrows range automatically
- Find Exact Commit: Run to completion; identifies culprit
- Review Commit: What changed? Why does it cause the bug?
- Code Path Bisect: Disable features/code paths; find what triggers bug
Anti-Patterns
- Assuming recent commit caused it; test assumptions with bisect
- Not using bisect on large commit ranges; manual search is slow
- Bisecting without reproducible test; need consistent yes/no answer
- Not reviewing found commit; understanding the bug matters
Further Reading
- Git bisect documentation
- Linux kernel debugging; git bisect is standard there