Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc • Hacker News Board

Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

#261

Post by IshKebab » Sat, May 09, 2026, 9:45 PM UTC

fao_ wrote: post #235

IshKebab wrote: post #218

Earlier quoted context omitted.

Fwiw you don't need unsafe for graphs or linked lists in Rust. At least not directly - these things can be abstracted. The petgraph crate is the most popular for graphs. I'm not sure about linked lists because linked lists are the wrong choice 99.9% of the time. I've written hundreds of thousands of lines of Rust and outside of FFI, I've written I think one line of unsafe Rust.

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It's not as simple as that. All software is abstraction and with any software if you go deep enough you'll find unsafe code.

E.g. look at a Python list. Is it safe? In Python sure, but that's abstracting a C implementation which definitely isn't safe.

If you look at Rust's std::Vec you'll find a very similar story - safe interface over an unsafe implementation.

It isn't as binary as you think.

Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

#262

Post by girvo » Sat, May 09, 2026, 9:45 PM UTC

mohsen1 wrote: post #75

Very impressive that they could do this so quickly because I have been on a similar project (porting TypeScript to Rust) for 5 months. But I guess I don't have access to Mythos and unlimited tokens. I'm also close to 100% pass rate. 99.6% at the time of writing. https://tsz.dev Rust is perfect for writing all of code using LLM. It's strict type system makes is less likely to make very dumb mistakes that other languag…

I’ve struggled to get Opus to not write the weirdest possible Rust, ignoring all idioms and so on. Any tips?

Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

#263

Post by IshKebab » Sat, May 09, 2026, 9:46 PM UTC

awesome_dude wrote: post #246

IshKebab wrote: post #218

Earlier quoted context omitted.

Fwiw you don't need unsafe for graphs or linked lists in Rust. At least not directly - these things can be abstracted. The petgraph crate is the most popular for graphs. I'm not sure about linked lists because linked lists are the wrong choice 99.9% of the time. I've written hundreds of thousands of lines of Rust and outside of FFI, I've written I think one line of unsafe Rust.

Show code

Err https://github.com/petgraph/petgraph

What are you asking for exactly?

Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

#264

Post by claude_delusion » Sat, May 09, 2026, 9:48 PM UTC

tempaccount5050 wrote: post #258

lioeters wrote: post #244

Earlier quoted context omitted.

Also a few days before that: > I expect OSS to go the opposite direction: no human contribution allowed. Slop will be a nostalgic relic of 2025 & 2026. We should have seen this coming after they got acquired by Anthropic, but it's still disappointing. I'm not against large language models as a technology, just thoroughly disgusted how these "AI" companies rose to power, eating the software industry and the rest of so…

Software companies have been about automating human labor since the invention of computers. It's the whole damn point. Why do you think finance used to be (sometimes still is) the head of the IT dept? Because we automated accounting away. Then typists. Then secretaries. Then drafting. Etc etc.

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Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

#265

Post by claude_delusion » Sat, May 09, 2026, 9:49 PM UTC

tracerbulletx wrote: post #255

dzonga wrote: post #212

Earlier quoted context omitted.

you know this whole exercise is both a marketing exercise and a way to make noise. would the world come to a standstill tomorrow if every Bun instance out there ran on Node.js ? they know their A.I can't sell without the noise that it's now on the edge of the frontier. this is hype. zig adopting a strict 'no LLM' policy affects the LLM vendors.

If you think Claude needs manufactured hype at this point to sell it you're delusional.

Anthropic literally has an astroturfing program:

https://news.ycombinator.com/item?id=47945021

Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

#266

Post by mikebelanger » Sat, May 09, 2026, 9:49 PM UTC

Interesting that ports can be written so quickly with AI. But that aside, I have to ask...why? You want a super performant bundler/runtime/package manager written in rust with TS support, Deno has this already.

Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

#267

Post by oytis » Sat, May 09, 2026, 9:50 PM UTC

zaptheimpaler wrote: post #236

scuff3d wrote: post #106

Earlier quoted context omitted.

Look what it can do in 6 days! Ignore the hundreds of thousands of hours put into the original architecture and test suite that made it possible in the first place.

This is such a bad faith argument. How long would it take a dev or a team of devs to do this with the same architecture and test suite? A hell of a lot longer than 6 days..

But what is the purpose? When you rewrite a project in another language, it's for engineers to be able to maintain and further develop the project better on some metrics due to advantages of the language. It doesn't hold when LLM does the rewrite, since there is no one who understands the code after that.

It's a good demonstration of capabilities, sure, but the result itself makes no sense. We'll have to figure out where these capabilities can bring real advantage

Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

#268

Post by nicce » Sat, May 09, 2026, 9:50 PM UTC

nesarkvechnep wrote: post #130

dmd wrote: post #58

Earlier quoted context omitted.

You want a better source than the actual author of Bun?

Authors can't exaggerate? Maybe some actual numbers can convince people.

Here: https://github.com/oven-sh/bun/issues?q=is%3Aissue%20%22Segm...

Around 2500 issues with segmentation fault.

Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

#269

Post by christopherwxyz » Sat, May 09, 2026, 9:52 PM UTC

yrjrjjrjjtjjr wrote: post #198

christopherwxyz wrote: post #152

Earlier quoted context omitted.

It’s disrespectful to immediately jump to adversarial conclusions from a simple desire to refactor and poor netiquette.

The right to be suspicious of the motives of powerful people is infinitely more important than protecting their feelings from being hurt by suspicion.

Protecting software creators, engineers, builders, and their work, regardless of their tools, is infinitely more important. Full stop.

Re: Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc

#270

Post by christopherwxyz » Sat, May 09, 2026, 9:53 PM UTC

erkat wrote: post #249

christopherwxyz wrote: post #152

Earlier quoted context omitted.

It’s disrespectful to immediately jump to adversarial conclusions from a simple desire to refactor and poor netiquette.

If experienced (in open source and corporate politics) developers would bet on Polymarket if the rewrite is going to be ultimately merged, which side would you bet on? What would the emerging odds be? My guess is 19/20 in favor of ditching Zig. I have followed many initial denials on a wide range of topics, not only rewrites, over the years. Like clockwork, most of them were lies.

I don't think most serious developers have time to watch prediction markets.