Probably because they said AI rewrote it in 11 days, yet haven't cut a release almost 2 months later. If their AI finished it, where's the release?
They ported enough of it to run a single app (Claude Code). Good job. But if I ported Linux to Rust and it was only capable of running a single app, should I be able say it was a complete port? We'd all agree that was misleading. It's the same with Bun.
The marketing lies simply backfired.
Producing a stable release for their community of code that had been written by AI in 11 days and had not yet been extensively tested in the real world would be grossly irresponsible.
Instead, they made the AI rewrite available as a canary release and shipped it for a month as part of Claude Code to millions of their own users.
If I pay someone to build a house and they left me a voicemail saying "Yep the house is finished, it only took us 11 days!" And then later, "No, you can't move in yet, still fixing some last-minute issues (there's no plumbing yet)." We would classify this as: a lie. And if you told it to your investors: fraud.
Would it really be so bad for Anthropic to admit that a project of this size takes months instead of weeks?
I'm not saying AI is not capable of this. I'm saying that their dishonest marketing has given ammo to their haters.
I think that's exactly what they've done by not shipping a stable release yet.
I don't think they've been pushing that "It only took us 11 days!" message nearly as hard as their critics suggest that they have.
I have to disagree here. From their blog post Rewriting Bun in Rust[0]:
> This Rust rewrite would've taken a team of engineers with full-context on the codebase a year of work. With 1 engineer using Fable & closely monitoring Claude Code, we went from start to 100% of the test suite passing on all platforms in 11 days. One engineer can do a lot more today than a year ago.
> I rewrote Bun in Rust using about 50 dynamic workflows in Claude Code run continuously over the course of 11 days.
`bun upgrade --canary`. You can use it today.
Keeping a large release, like a total rewrite, on canary for a while to iron out bugs is a very reasonable software engineering practice.
I love reasonable engineering practices, like throwing out your entire codebase and rewriting it in a whole ass different language :)
are you a software engineer?
What constraints? What right practices? What ideal combo? Maybe this whooshed over your head but I was sarcastically pointing out that just because you can do something doesn't mean it's a reasonable engineering practice or, uh, an "ideal combo."
> are you a software engineer?
Uh negative I am a meat popsicle
How many days must a rewrite take for it to be good in your opinion? How does time spent correlate with quality?
> a single app
I mean this is a very silly way to describe one of the most used developer tools in the world, don’t you think?
Nope. I also wouldn't lie and say it's complete when it isn't.
>Bun v1.4 makes Bun faster, smaller, use less memory and gives the team incredibly powerful tools for systematically improving stability going forward: Rust's borrow checker, Miri (which runs for a growing chunk of code in CI), LeakSanitizer, and 24/7 coverage-guided fuzzing for parsers. There's still more to refactor, but things are off to a great start.
Perhaps you never perused beyond the HN headline?
> I rewrote Bun in Rust using about 50 dynamic workflows in Claude Code run continuously over the course of 11 days.
Is this Schrodinger's rewrite?