Rewrite Bun in Rust has been merged • Hacker News Board

Re: Rewrite Bun in Rust has been merged

#191

Post by veidr » Thu, May 14, 2026, 2:37 PM UTC

tkel wrote: post #4

Turns out "its just an experiment, you all are overreacting" was just a lie to damp criticism. https://news.ycombinator.com/item?id=48019226

You have no idea if it was a lie or not. I routinely have my clanker fleet spend a couple days toiling on some crap that I assume I will throw away, but it turns out pretty awesome, so I keep it.

It's entirely plausible that when that comment was posted, he doubted it would work well enough to keep.

(Sensible default for LLM code, btw. But sometimes it works great.)

Re: Rewrite Bun in Rust has been merged

#192

Post by nDRDY » Thu, May 14, 2026, 2:38 PM UTC

j-pb wrote: post #171

On one hand I kinda feel validated for having jumped ship on Zig 3+ Years ago[1] and moving everything to Rust[2], with the language simply being too unstable and unsafe in my eyes, despite my love for comptime and people arguing that Bun and Tigerbeetle were proof that it wasn't the languages fault. But I also feel bad for the Zig project to loose one of their flagship projects, because while I find the project ulti…

I doubt the Zig maintainers will miss the giant PRs from Bun!

Re: Rewrite Bun in Rust has been merged

#193

Post by xydone » Thu, May 14, 2026, 2:39 PM UTC

szmarczak wrote: post #165

4b11b4 wrote: post #147

Earlier quoted context omitted.

Same, just gonna stick with node. On the other hand, the trial by fire will be interesting to see... long term I can only imagine the kinks will surely work themselves out

Wait till you hear about https://github.com/nodejs/node/pull/61478

This is a PR that has been getting reviewed since the end of January. The Bun port branch was created 9 days ago.

Re: Rewrite Bun in Rust has been merged

#194

Post by debugnik » Thu, May 14, 2026, 2:41 PM UTC

surajrmal wrote: post #155

debugnik wrote: post #83

Earlier quoted context omitted.

Having seen some of the diffs, it's already going wrong in my view.

If most of the glaring problems are addressed (massive unsafe usage), and metrics show improvement (less crashes), then did it really go wrong? The fact the code is not idiomatic is less interesting, because that can be addressed incrementally. Let's wait 3 months and reflect.

I'm thinking regressions and broken tests. Bun is already known to segfault a lot and their existing tests were rather lackluster, the Rust port being just as unsafe would be the least of their problems.

Re: Rewrite Bun in Rust has been merged

#195

Post by aarjaneiro » Thu, May 14, 2026, 2:42 PM UTC

So many of the code comments on the new port concern only discussion on how it was ported, usually referring reader to the original zig implementation.

So now I'd basically be reading 2x the amount of comments and code to understand _why_ anything is happening.

Re: Rewrite Bun in Rust has been merged

#196

Post by tasuki » Thu, May 14, 2026, 2:44 PM UTC

embedding-shape wrote: post #170

tasuki wrote: post #135

Earlier quoted context omitted.

You, nine days ago[0]: > I work on Bun and this is my branch > This whole thread is an overreaction. 302 comments about code that does not work. We haven’t committed to rewriting. There’s a very high chance all this code gets thrown out completely. Maybe... it wasn't such an overreaction? [0]: https://news.ycombinator.com/item?id=48019226

You're not alone in voicing this, another (now dead) comment did it earlier too with a bit more of an emotional response ( https://news.ycombinator.com/item?id=48134229 ). Still, do you folks never do something to see how you feel about something, then chose to go one way or another? I'm not sure why it's so hard to see that it was an overreaction at the time, because it was an experiment, then at one point it stoppe…

Yes sure it's ok to change your mind. But don't you think the people Jarred accused of "overreacting" in retrospect didn't?

Re: Rewrite Bun in Rust has been merged

#197

Post by TiredOfLife » Thu, May 14, 2026, 2:45 PM UTC

frangonf wrote: post #54

So the geniuses in the datacenter prefer to rewrite the full codebase in another language instead of maintaining and improving its own fork or contributing to make the current language better. Impressive to rewrite 1MLOC in a week yes, but this is more of a job of a million monkey programmers crammed in a datacenter than a bunch geniuses. And I would know, since I'm a monkey programmer who is in danger now... Or mayb…

> or contributing to make the current language better

The people making Zig have said they don't want that.

Re: Rewrite Bun in Rust has been merged

#198

Post by asciimoo » Thu, May 14, 2026, 2:45 PM UTC

embedding-shape wrote: post #188

asciimoo wrote: post #185

Earlier quoted context omitted.

> For who? What you say is true for everyone who doesn't know Rust (before Zig), and not true for everyone else, same as it always is been, for every single FOSS project out there. Even if you are fluent in rust, it is going to require significant efforts to contribute to a new 1M LoC codebase. > Open source literally isn't about you, let people run their projects as they so wish, them making choices they think are b…

> Even if you are fluent in rust, it is going to require significant efforts to contribute to a new 1M LoC codebase. Of course, but this is true for any project or any language, can hardly be disrespectful of me to chose Clojure just because you don't happen to know it? That sounds crazy to me. > Contributors are the most valuable assets of an open source project You're talking about something else. Open source is li…

> Of course, but this is true for any project or any language, can hardly be disrespectful of me to chose Clojure just because you don't happen to know it?

Nobody said that the problem is not knowing rust. The problem is changing the whole stack of a project overnight. This requires significant effort to get familiar with, even if a contributor have all the experience in the world with the new stack.

> Don't mix concerns here, you're talking about "open development"

Call it however you want, bun could not be the tool it is without its >800 contributors.

Re: Rewrite Bun in Rust has been merged

#199

Post by j-pb » Thu, May 14, 2026, 2:48 PM UTC

nDRDY wrote: post #192

j-pb wrote: post #171

On one hand I kinda feel validated for having jumped ship on Zig 3+ Years ago[1] and moving everything to Rust[2], with the language simply being too unstable and unsafe in my eyes, despite my love for comptime and people arguing that Bun and Tigerbeetle were proof that it wasn't the languages fault. But I also feel bad for the Zig project to loose one of their flagship projects, because while I find the project ulti…

I doubt the Zig maintainers will miss the giant PRs from Bun!

I'm pretty sure they'll miss the full developer salary that Oven used to sponsor them, which they no longer do. I'd wager one doesn't do a rewrite like that, if you are in great personal standing with the language foundation.

That same "just don't use it" attitude was what drove me away from Zig btw. I would have been fine in restricting myself to a somewhat stable subset, e.g. if, loop + function calls, but they didn't want to provide any tiered stability guarantees for the language.

Opinionated is great, no local minima is great, but you have to accept that if you don't want to engage with the needs of your (professional) community then what you do is a hobby project. A very cool hobby project beloved by thousands, but a hobby project.

Re: Rewrite Bun in Rust has been merged

#200

Post by padjo » Thu, May 14, 2026, 2:50 PM UTC

Will be interesting to see how this pans out. Some people will see minor issues as proof that AI is terrible, but honestly if this gets released and is relatively uneventful it just highlights how the art of building software had changed completely in the last few years.