kani VS watt

This is also the backend for Kani - Amazon's formal verification tool for Rust.

https://github.com/model-checking/kani

Nice read! Rust has pushed, and will continue to push, the limits of practical, bare metal, memory safe languages. And it's interesting to think about what's next, maybe eventually there will be some form of practical theorem proving "for the masses". Lean 4 looks great and has potential, but it's still mostly a language for mathematicians. There has been some research on AI constructed proofs, which could be the best of both worlds because then the type checker can verify that the AI generated code/proof is indeed correct. Tools like Kani are also a step forward in program correctness.

Ease setup in Amazon Linux 2 by @adpaco-aws in #2833

Limit --exclude to workspace packages by @tautschnig in #2808

Here's a summary of what's new in version 0.38.0:

> those applications need the proof for correctness so that more dangerous code---say, what would need `unsafe` in Rust---can be safely added

There are actually already tools built for this very purpose in Rust (see Kani [1] for instance).

Formal verification has a serious scaling problem, so forming programs in such a way that there are a few performance-critical areas that use unsafe routines seems like the best route. I feel like Rust leans into this paradigm with `unsafe` blocks.

[1] - https://github.com/model-checking/kani

Enable concrete playback for failure of UB checks by @zhassan-aws in https://github.com/model-checking/kani/pull/2727

Change default solver to CaDiCaL by @celinval in https://github.com/model-checking/kani/pull/2557 By default, Kani will now run CBMC with CaDiCaL, since this solver has outperformed Minisat in most of our benchmarks. User's should still be able to select Minisat (or a different solver) either by using #[solver] harness attribute, or by passing --solver= command line option.

Add support for sysconf by feliperodri in #2557

The precompiled binary is not a sandboxed WASM binary. Despite the name "watt" it has nothing to do with https://github.com/dtolnay/watt . You can look at the actual code to see for yourself.

* Related: watt is one approach to pre-compile proc-macro crates using WASM.

In addition to thiserror and anyhow, our resident superhuman Rust-improving Robot, dtolnay, also developed an experiment in distributing precompiled proc macros as WebAssembly named Watt and, though I never bothered to create a Zulip account so I don't know what was said, I'm told there has been discussion around the idea of implementing something in that vein.

I think when we have Cranelift, Mold, and maybe Watt all working together then compile times will basically be a non-issue. It'll be a few years though.

Check out https://github.com/dtolnay/watt - it's a really interesting solution to the problem!

I really like the idea of Watt: https://github.com/dtolnay/watt Run macros in a wasm sandbox so they can't touch anything you don't explicitly allow.

I really wish there was more interest in getting something like Watt upstreamed.