Bun 1.4 Rust rewrite is not looking good?(tipiirai.com) |
Bun 1.4 Rust rewrite is not looking good?(tipiirai.com) |
Here... I'll go first. `bun repl` in 1.4-canary has some rendering issues where characters get overwritten that I had previously not observed in 1.3.
For the internet at large no, but the comment doesn't make sense. It's not as if volunteers don't post all kinds of checks, and reports, and benchmarks, and deep dives anyway.
Idk why people have become so invested in this.
> Unused code is one issue. A project called Buz[1] found over 11,000 lines of dead code from the Rust port. [1]: https://github.com/jazzzooo/buz
When in fact Buz is a fork of the pre-Rust Zig version of Bun.
The OP has no credibility.
We will, however, be left to scour the ruins of the financial devastation if this goes sour.
He _has_ sold, though. Anthropic purchased Oven back in Dec. 2025.
Or your probably was about whether it was big $$$ or not?
People _really_ want there to be success stories for llms and they will go through all lengths to discredit and disparage folks questioning the space.
But I still strongly believe the project makes a lot of sense, and I genuinely think these issues can be solved by 2028, if the project keeps its focus on stability instead of another SDK for SQL, web sockets, image compression, or whatever comes next
If you check the maintainer X, he's asking Claude for what features to implement next. Not only stabilizing isn't the priority, even the features implemented are random.
Link?
To me that sort of stunt sounds like blatant attempts to distract the audience away from relevant topics.
Apart from pro-AI or anti-AI posturing how have the last few months not looked good for Bun, exactly? I use it daily and I've seen basically zero regressions. I get it, you don't like AI or you like Zig over Rust, or whatever. I just haven't seen any serious argument that Bun has somehow become worse software.
> The project has over 5k open pull requests, which is the largest number of pull requests I’ve seen.
Terrible argument, and not really an argument at all.
> The biggest worry is, of course, the code itself.
I agree, so look at the code and point out what's wrong with it.
Insofar as Andrew Kelley is concerned, it's obvious he has an axe to grind and is salty about Bun embarassing Zig (which he freely admits). Not sure why you'd invoke an unreliable narrator as some sort of final nail in the coffin.
I suppose it’s one thing to rewrite code and make tests pass. But a lot of my own CPU cycles when coding go to making the code understandable, modular, editable etc. IME Claude is not great on these.
Maybe it doesn’t matter? Maybe the spaghetti makes sense to Claude, and when you say “hey add this feature”, no problem?
But maybe it will turn into a worse ball of spaghetti, with no nicely curated tests, hacks on hacks on hacks and never ending loops of whackamole of “just change this one line and rerun tests”.
I can imagine both - let’s see.
They were pleased to be faster than Go in the "Hello World" benchmark, but unfortunately, they lag behind Node.js and Deno in complex real-world workloads.
Having said that I would have a bit more confidence in things if release just got back to a normal pace.
- I have a couple of projects that handle images. I was including Sharp, but since these are side projects in a small VM, often a redeploy that recompiled Sharp just crashed the full VM (out of memory). Bun includes Bun.Image[1] natively, which is built around Sharp's API, so swapping Sharp out was very easy, and now deploys are a breeze (and swapping it in would be just as easy).
- Bun's JSX support is a godsend. I've replaced almost all my side projects that were backend rendered from Pug, Handlebars, and other various templates I used to have to just pure JSX. Heck, this made it trivial to make a side projects where the Favicon was a dynamic SVG [2]
[1] https://bun.com/docs/runtime/image
[2] https://stocksreader.com/portfolio?%5Egspc=10&amzn=10&msft=1...
Have you tried 1.4?
I would love to know how much token they spent on the rewrite starting from deciding to rewrite till they actually ship. I assume since the beginning of this whole rewrite saga they have been spending tokens on it every day so the number that Jarred mentioned in his blog post has increased a lot since then.
Also assuming the future releases will be done through AI as well I wonder how much it will cost for each of them.
Why not release 1.4 (or 2.0 or whatever) then? It won't get picked up by lots of tooling and won't get allowed in many "no pre-release in prod" shops until then. It had plenty of issues before (many thousands of open issues) so a few thousand more is hardly a big deal...
If you actually want an answer to your question, ask Jarred ... you won't get it here.
At the same time this specific rewrite is being used to drive the narrative that reading the code is counterproductive.
If they had delivered their promises, they might have convincingly delivered that argument.
...but the cost keeps going up and up and up and up! If it was only the token costs it might still be economically viable, but I'm imagining that when you add in the pro-rated salaries of the human engineers this would start to look like a financial blunder even if it released today.
It's true that I don't want a success story told about a failure, because then replicating the "success" would likely produce lots more bad outcomes
It may also lead to the A.I. musical chairs game stopping and a multi-trillion dollar collapse of the stock-market and, most likely, the financial system. Hopefully we'll be able to buy DRAM and other stuff that uses it cheaply again.
I mean there's so much cruft on the internet about people talking how revolutionary these code generators are and that they fixed 5 years worth of technical debt in 2 months etc. etc. Considering the multi-trillion dollars involved I don't believe we can trust anything we read anymore. Many of these proponents are nothing but paid shills.
Nah, they'll just shift the goalposts again.
> Our conclusion is deliberately modest: under the conditions Prisma Compute cares about, the Rust rewrite behaved better than the stable release we had been testing. That was enough to change what we shipped.
need 5 trillion more Opus token
Your whole scientific endeavor in this seemed to thrive on the rock solid foundation of tweets.
And all those referencing of the Kelly post makes this even more of a clickbait. All you had was to put all the ingredients of a post that will draw the crowd but offer very little on the subject matter it purported to discuss
The article lists various promised release dates, are they incorrect?
The blog post states quite clearly that Bun stopped posting any release.
During the Zig/pre-Rust days, Bun was posting s new release each 2-3 weeks.
Since then, Bun's Rust migration is correlated with a complete stop of Bun's release cadence.
For most, they are still waiting for official release so they could make their own judgment, the problem is that it is still not released. I guess we should just wait a little longer.
What I'd like to see in the meantime is what are the biggest blockers to the release. Maybe Bun has a milestone list somewhere, I couldn't find it.
> Terrible argument, and not really an argument at all.
Technically, maybe.
But when you consider for a moment that in this pile of slop some PRs were crafted by actual people who trusted Bun and Jarred... and whose trust has been flushed down the toilet by the Rust rewrite. Well, maybe that's the price of progress. Or maybe that's a grave mistake.
I'm not yet sure which is it.
The article answers this. hint: they're not shipping.
> I get it, you don't like AI or you like Zig over Rust, or whatever
The article doesn't argue for either of these. hint: it's arguing that the team is not shipping.
> Terrible argument, and not really an argument at all.
It's an argument for the devs not shipping
> I agree, so look at the code and point out what's wrong with it.
It's not being shipped.
Hope that helps.
They're shipping though.
Claude Code and many others use it. There's just not been a "public" release.
You should have lead with “What is it now?”
What are you talking about? I'm running 1.4 canary (the Rust rewrite) right now.
λ bun --version
1.4.0
> Buz is an early-stage experimental fork of pre-Rust Bun.... Over 11,000 lines of dead code removed from upstream Bun.
edit: There's also nub which is built on top of Node.js and removes some rough/legacy edges: https://github.com/nubjs/nub
You need a "separate" tool called npm to install packages. It's dead slow so they added corepack. Another extra tool. Then you use it to install yarn or pnpm. Another extra tool. It might still be slower than bun...
In the past you need to transpile typescript with other tools. It can only run js out of the box. The later fix was a wasm build, which means slower than it could be. Another 1/2 job.
Many more examples in many areas but anything Node tries to do itself feels 1/2 baked.
Bun and Deno are faster than Node because it is a 1/2 job at its core. It has v8. It has the tools. It could be done but no. It did nothing for years until Deno and Bun came on the scene to nudge it.
But, for people who don't like AI, they also refuse to believe that AI could be good at any particular workflow. Which is just obviously not true, there are workflows that AI is really good at. Language re-writes are one of them. They're almost mechanical in nature and trivial to check via tests. So, the perfect use-case for an LLM.
I'm not saying the Bun re-write is any good, but the underlying concept is sound. If ever there was a tool to do a language re-write, it would be a high quality LLM.
A bizarre accusation. It's a fork of Bun that says they removed the dead code. All you have to do to see the diffs is look at its history. Most of the commits are code removal.
It's a fork of Zig bun, though, not Rust, so hardly relevant to the AI argument.
- esbuild - this is normally for TS compilation, which Node can run natively now by stripping types: https://nodejs.org/docs/latest/api/typescript.html#type-stri...
- jest/vitest: Node has a test runner: https://nodejs.org/docs/latest/api/test.html
- dotenv: Node can read .env files: https://nodejs.org/docs/latest/api/cli.html#--env-filefile
Performance, maybe you're right - but if you're doing any IO, I doubt the runtime is really the bottleneck.
But if not he can reach out
He just says whatever predetermined shit he was supposed to say.
They do seem to have just merged in support for Web Workers though, which I've been following for a while: https://github.com/nodejs/node/issues/43583
So I don't think they're opposed to standardising, but it's trickier when you have some past cruft built up. Lets not forget that the fetch() standard was built for browsers, and is a bit of a stretch to make it work on servers at all. You have to diverge from the fetch spec to even make it make sense in a server environment (with things like Cookies handling off the top of my head).
Which leads to confusing things like the fact that there are two streams APIs in Node now:
Streams: https://nodejs.org/docs/latest/api/stream.html
Web Streams: https://nodejs.org/docs/latest/api/webstreams.html
And they have to support going back and forth between the two: https://nodejs.org/docs/latest/api/webstreams.html#nodejs-st...
It's exactly the same story for crypto as well. Node created it's own standard, Web standards emerged, Node has to support both:
https://nodejs.org/docs/latest/api/crypto.html
https://nodejs.org/docs/latest/api/webcrypto.html
Fwiw I think it's good they're not removing the legacy code, but they should probably do a big cleanup major release and lean into the modern standards and remove the old stuff. But there's obviously push back in doing so... and probably stuff you can do in the old modules that you can't do in the new and vice versa.
When we used to code by hand, Bun used to have an amazing list of articles on how to convert from almost any kind of streamable to almost any other type. I used it a lot, and that was when I started liking Bun so much.
The bun rewrite is looked to as proof that this sort of full-throttle vibecoding is the future of software development, at least for large porting projects like this one, and for many people on this site that is a high stakes question.
To prove that, a proper release is needed, and the Bun community needs to adopt it. There's a huge partisan eagerness to declare the Claude Code release or anecdotal experiences on the canary as victory, but the viability of 1.4 hasn't been demonstrated until it has been released and adopted by the bulk of the community.
There isn't actually any hurry on that. Nobody needs Bun 1.4 tomorrow. It's Jarred that keeps saying it'll be released tomorrow, while the code churns at an astonishing rate (see below). People with a skeptical outlook will inevitably suspect that he doesn't have confidence in the release and is struggling to acquire it.
Github insights for the last week:
> Excluding merges, 57 authors have pushed 349 commits to main and 6892 commits to all branches.
> On main, 2026 files have changed and there have been 189,502 additions and 133,836 deletions
To who? You?
> To prove that, a proper release is needed
For who? Who is trying to prove what?
> It's Jarred that keeps saying it'll be released tomorrow
There's no official blog... he's just rambling on x?
> Github insights for the last week
That's the problem with the rest of your post. Bun is no longer VC-fueled open source project. It got sold to Anthropic.
> There's a huge partisan eagerness to declare the Claude Code release
Hence there isn't. The Claude Code release is for its own use.
And yes, I think he was not genuine there and that they had indeed fully committed to the rewrite prior to that point and comment.
If you're not aware of any of this, how are you arguing it was communicated clearly?
I do have to agree with the author about Jarred's false claims about release dates though. Really not sure why he keeps doing that.
The most obvious benefit Rust can give them is being safe from memory leaks. This is hardly controversial: it has been a Zig design choice that memory leaks are the developer/user's responsibility. They have already demonstrated to have fixed several of those [0].
Marketing-wise, it has been an obvious success. Dunno if that matters.
Seems pretty simple to me: if the software works, the port has been successful.
If this is unsatisfactory, another way to think about the question is to ask "what would make you conclude it has failed?" That requires a sharp choice.
What's interesting tho it's that it can go from apparent marketing success to a big failure as the release keeps getting postponed.
P.S. Nor does new user parenting my comments.
Later on used Intel Processor Trace in a similar fashion for even finer (mc-dc) coverage.
Coverage tools are very useful, if a bit hard to use...
I think GP was pointing out how bun's release cadence stalled and the project is going nowhere at the moment.
https://github.com/oven-sh/bun/releases
The project was pretty healthy up to 1.13.14, but since may they stopped shipping anything.
That's quite odd for a project that just went through a major rewrite and is lauded as being developed primarily by LLM coding assistants.
Personally I expected the release cadence was going to go through the roof, but instead it flat lined.
That's not credible at all. I mean, after a major release there are tons of low-priority low-hanging fruit issues that can be quickly sorted out. That's the nature of a release process.
However, Bun stopped releasing anything. Even after lauding it's AI push,which can easily chomp through small tickets.
It's been a couple of months since the major push. I repeat: the release cadence of a mature, stable codebase as the Zig one was at 2-3 weeks. A messy rust rewrite packed with unsafe code, which is prime ground for small bugfixes and correctness fixes, led the project to grind to a halt.
No one looks good in the picture.
There's clearly something wrong in their confidence about Rust Bun: If it isn't ready they should have said "whenever it's done", and if it is they'd have met some deadline by now. I suspect the speed was supposed to be part of the stunt, yet they seem to have encountered the 90:90 rule.
That’s not like … a design flaw or something, just a common class of error Rust can’t save you from.