Bun 1.4 Rust rewrite is not looking good

# Bun 1.4 Rust rewrite is not looking good • Tero Piirainen Source: [https://tipiirai.com/writing/bun-rust-rewrite-worries](https://tipiirai.com/writing/bun-rust-rewrite-worries) I care about Bun\. I have been rooting for it since the initial release in 2022\. I switched all my development from Node to Bun\. I used it in the development of the[Nue framework](https://nuejs.org/)and now with my new project[Hertta](https://hertta.ai/)\. The last three months have not looked good for Bun\. It started as one of the most impressive individual engineering projects I have seen, but has now turned into this weird AI\-powered creature with continuous false promises and an increasingly frustrated community\. ## [In the next version of Bun](https://tipiirai.com/writing/bun-rust-rewrite-worries#in-the-next-version-of-bun) In the next version of Bunused to be a positive tweet to watch for\. For years it meant a feature had been implemented, tested, and would ship in a few days\. This changed after the Rust rewrite\. Now the posts are false promises about the upcoming release: It’s now three months and counting since the last stable release, the longest gap in Bun’s history since 2022\. Nothing unusual there\. Software slips, that’s normal\. It’s just that an account which used to communicate with real dates and real numbers has switched to vibing\. And the user reaction is what you’d expect after constant false promises: [> @jarredsumnerokay I’m editing blog post it’s mostly done if I say a date you won’t believe me but let’s say tomorrow](https://xcancel.com/jarredsumner/status/2089542355384947021)We totally believe in you, Jarred Rejoice fellas, tomorrow in Jarred Standard Time zone means we have a new blog coming next week\. You won’t care, but personally I am switching to go now\. It’s not even funny, you are just stringing your users along again and again\. How can we believe you? You always make promises that you can’t keep, tomorrow, next week, Monday\.\.\. If you need 2 months to release it you can just say that instead of saying you’ll ‘release it tomorrow’ every week ## [Bun on GitHub](https://tipiirai.com/writing/bun-rust-rewrite-worries#bun-on-github) The Bun 1\.4 rewrite is a big bet on AI\. In the past month, 15\.8k commits came fromrobobun,1\.6k commits fromautofix\-ci\[bot\],and 790 commits from Jarred\. [> 6 months ago, most of Bun’s PRs came from people prompting Claude\. Nowadays, most of Bun’s PRs come from Claude prompting Claude\.](https://xcancel.com/jarredsumner/status/2088856044139323634#m)The project has over[5k open pull requests](https://github.com/oven-sh/bun/pulls), which is the largest number of pull requests I’ve seen\. For comparison,[OpenClaw](https://github.com/openclaw/openclaw/pulls)has 2\.2k, and[React](https://github.com/facebook/react/pulls)has 441\. GitHub recommends staying under 1,000 open PRs against a single branch before mergeability checks start timing out\. The biggest worry is, of course, the code itself\. In the early days Jarred’s work was inspirational\. I thought he was a true Zig talent, until I read Zig creator Andrew Kelley’s[thoughts on the Bun rewrite](https://andrewkelley.me/post/my-thoughts-on-the-bun-rust-rewrite): [> We became increasingly horrified at the programming practices we saw in Bun’s codebase\. Hacks on top of hacks\. Abuse of assertions\. Jarred was already writing slop well before he had access to LLMs\.](https://andrewkelley.me/post/my-thoughts-on-the-bun-rust-rewrite)## [What was the problem with Zig?](https://tipiirai.com/writing/bun-rust-rewrite-worries#what-was-the-problem-with-zig) This rewrite is*the*most closely watched real\-world test of whether AI agents can take over a production codebase with a human mostly directing rather than reading\. Anthropic’s own reputation is also on the line: if this goes well, it is real proof of what agentic coding can do\. If it goes badly, it will send a signal in the opposite direction\. The number of unsafe blocks in the Rust code suggests the rewrite did not deliver the memory safety that was given as the reason for doing the rewrite in the first place\. Instead this rewrite feels more like an Anthropic ad\. And was Zig really the problem? Bun’s early identity was built on Zig: its performance, its fast compile times, its low friction, its direct memory control with a small team\. It feels like Jarred and Anthropic decided early on that this was going to be written in Rust, and used Zig’s memory issues as the excuse to let the world know how powerful Claude is\. A rewrite like this would make great headlines, and it certainly did\. Now we’re looking at the long tail of issues from the rewrite they didn’t prepare for\. Maybe Bun should have put that same AI\-assisted effort into disciplined, human\-understood Zig instead of a full language change\. I never saw Jarred seriously engage with this option\. And ‘tomorrow’ has come and gone\. Still no v1\.4\. `¯\\\_\(ツ\)\_/¯`