Git bayesect
Dev tools
git bisection
SHOW HN2026
How HN took it
6 positive, 21 neutral or asking, 2 mixed, 0 critical, out of 29 comments about the project. Thread score +0.20.
Idea: 5 for, 0 againstDesign: 1 for, 0 against
The thread, comment by comment
Each row is a top-level comment and its replies, in HN's order. Select a cell to open that comment on HN.
positive neutral or mixed critical about another commenter or something else the maker
What HN said
What people liked
Elegant math and Bayesian approach
From 3 comments
Really fun work, and the writeup on the math is great. The Beta-Bernoulli conjugacy trick making the marginal likelihood closed-form is elegant. We ran benchmarks comparing…
rs545837 on HNNice! I implemented a similar thing a while back: https://github.com/Ealdwulf/BBChop I'm going to have to check out how you got linear time with Shannon entropy, because I used…
ajb on HNthe test-only commit case is an interesting edge for the priors. when bisecting flakiness regressions, commits that only touch test files are often the actual culprit (tightened…
volume_tech on HN
Useful for flaky tests and CI efficiency
From 2 comments
Integrating Bayesian priors into bisection is exactly how debugging feels in your head, but formalized. The biggest win here might be in CI efficiency -- if you have a finite…
Caum on HNUseful for tests with LLM interactions.
davidkunz on HN
Objections
Posterior can mislead; top commit may only shift timing, not be the cause
From 1 comment
Bayesian bisection helps when the failure rate shifts enough to measure. Once a bug rides on scheduler jitter or some external side effect you don't control, the posterior gets…
hrmtst93837 on HN
Assumes equal test cost per commit, ignoring slow rebuilds
From 2 comments
Does this tool assume it takes the same amount of time to test two commits once as it does to test one commit twice? Maybe true for interpreted languages, but if you're waiting…
IshKebab on HNrecompiling can be high constant overhead
__s on HN
Requests
Support for noisy benchmark scores instead of pass/fail
From 1 comment
Super cool! A related situation I was in recently was where I was trying to bisect a perf regression, but the benchmarks themselves were quite noisy, making it hard to tell…
Retr0id on HN
Option to consider only merge commits
From 1 comment
My team doesn’t always have cleanly bisectable branches being merged to main —- it’s not uncommon to see “fix syntax error” types of commits. But, to merge we need to have all…
belden on HN
Questions
What is the practical application and how does it work
From 1 comment
I hope this comment is not out of place, but I am wondering what the application for all this is? How can this help us or what does it teach us or help us prove? I am asking out…
SugarReflex on HN
How does it compare to git bisect accuracy at fixed budget
From 1 comment
> We ran benchmarks comparing bisect vs bayesect across flakiness levels. At 90/10, bisect drops to ~44% accuracy while bayesect holds at ~96%. At 70/30 it's 9% vs 67%. I don't…
sfink on HN
Alternatives named
git bisect
From 2 comments
> I know git-bisect doesn’t support this It does.
menaerus on HNReally fun work, and the writeup on the math is great. The Beta-Bernoulli conjugacy trick making the marginal likelihood closed-form is elegant. We ran benchmarks comparing…
rs545837 on HN
BBChop
From 1 comment
Nice! I implemented a similar thing a while back: https://github.com/Ealdwulf/BBChop I'm going to have to check out how you got linear time with Shannon entropy, because I used…
ajb on HN
CUSUM change-point detection
From 1 comment
The HMM framing connects to change-point detection. CUSUM (Cumulative Sum) charts solve a related problem: detecting when a process parameter has shifted by accumulating…
tazsat0512 on HN