I just launched cargo-vouch, an by Satyawan SinghI just launched cargo-vouch, an by Satyawan Singh

I just launched cargo-vouch, an

Satyawan Singh

Satyawan Singh

I just launched cargo-vouch, an open-source Rust tool that proves a function can't panic. No tests to write, no annotations to add. Point it at a .rs file, and it builds a Kani proof harness for every function, then checks every input in bounds. Each function comes back with one of four verdicts: šŸ”“ BUG, with the exact input that triggers the panic 🟔 UNGUARDED, safe except at type extremes like i32::MAX 🟢 VERIFIED, provably panic-free ā³ INCONCLUSIVE, when it cannot decide Why I built it: AI writes Rust that passes cargo test, then panics on an edge input nobody tried. For example, numbers.iter().sum() looks fine until something hands it [i32::MAX, 1]. I ran it on 11 functions GPT-4o wrote and graded. GPT-4o's own grading got 4 of them wrong: it passed three that overflowed and failed one that was fine. cargo-vouch called all four correctly, with the triggering input for each real panic. The honest limit: it is built for loop-light code. Parsers and loop-heavy functions return INCONCLUSIVE, never a false pass. I would rather say that than oversell it. If you write Rust, I would like your feedback. Repo - https://lnkd.in/eHirVFQq cargo install cargo-vouch #rustlang #opensource #formalverification
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Posted Jul 22, 2026

I just launched cargo-vouch, an open-source Rust tool that proves a function can't panic. No tests to write, no annotations to add. Point it at a .rs file, ...