[thayne]

Zig and Rust are significantly different languages. If bun has a good architecture in zig (which I don't know if it does or not), that doesn't necessarily mean it had a good architecture for rust. A direct translation of zig code would probably result in pretty unusual rust code, and probably a lot more unsafe usage than if it had been originally written in rust.

[adampunk]

I don’t really understand this objection. For every tool that I use, am I supposed to divine the best underlying language for it and then determine whether or not it is written in that language? Don’t I have better things to do?

[kikimora]

Because of borrow checker you would build data structures differently in Rust compared to Zig. Automated translation simply maps Zig constructs onto unsafe Rust code. I have no idea how feasible it is to go from totally unique way of using Rust to mimic Zig to idiomatic Rust.

[adampunk]

I understand that. That’s a specific example of an inaptness moving from one language to another. That’s not what I’m talking about.

I am asking if we are expected to understand this hypothetical condition about all possible tools that we use. Should I have to worry that something is written in Python when it should’ve been written in C? It just seems like that in order to have a big concern here, I had to be really invested in what language Bun used. I guess the whole matter makes more sense if people are REALLY mad about something else and the choice of language is supposed to serve as a more respectable thing to be mad about.

[thayne]

I'm not saying that bun shouldn't be written in rust. I'm saying that since it was originally written in zig, there were undoubtedly architecture and design decisions that were made that made sense in zig, but not so much in rust. When rewriting something in a different language, especially one significantly different than the original it is common to need to re-architect some things, and mechanically translating line by line from one language is probably going to result in some low quality code, even if the original was decent.

I think that using AI to translate bun from zig to rust might produce a good starting point. But it was done one file at a time, with minimal human review, and I'm skeptical that the result is quality maintainable code.

[adampunk]

I don't want to say that skepticism is unwarranted, but I'm not sure we apply this level of scrutiny with any kind of defensible evenness. I just can't think of a single open source project I use where I'm aware of their refactor cadence and practice. I'm just...not checking in on their feature branches and stuff, and I think most people aren't. I couldn't tell you if the uv maintainers work at 3AM while high on drugs or at 9:30 AM wearing FORTRAN blue ties.

I dunno. I think my sense here is that the bun maintainers did something shocking and dramatic using AI and people are shocked and dramatized. They're not WRONG to be so. But I don't know that the shock comes out of any generalized duty of care we have toward open source tooling. I think the uncomfortable point that bun has been releasing for 6 months with smaller AI code edits hasn't really been reckoned with. If we were actually this invested in what was happening, the migration would've begun months ago when it was clear they were using agents to ship code faster than they were willing to review.

[fragmede]

What is that tool in relation to the rest of your workshop though? If it's a simple hammer that you can swap out for $20 and you only use it once a month, who cares what kind of metal it's made out of, as long as it works. But if the $6,000 4-axis CNC machine that's at the heart of your machine shop and every minute of downtime on it costs you money, if it's starting to rust, no, you don't have better things to do than to look into what it's made of.

[adampunk]

Yeah what if the tool is a JavaScript runner released for free?

What is being expressed here about Bun is using the language of due diligence but doesn’t seem to adhere to any of the sensibilities. Should we all be auditing our toolchains to understand internal decisions that each toolmaker undertakes? Maybe! DO WE? Absolutely not. The level of scrutiny bun is getting is *unusual*. They just did an unusual and dramatic thing, so it’s not surprising. But I just don’t believe that bun is being deprecated due to normal engineering discipline that we are constantly carrying and applying everywhere. That’s…just hard to buy.

[fragmede]

We're all only human, so the deprecation happening is gonna have some biasing going on due to how people feel about AI, yeah. JavaScript runners is a whole ecosystem separate from, say, Python. If Python went and said that the next version of Python, we're using this new AI transpiled runtime that we baked for nine days, people would also freak out "due to normal engineering discipline that we are constantly carrying and applying everywhere." The real question then is just how far off from normal is it? Maybe you don't do audits that you think you should be doing, but eg moving from Python 3.10 to 3.12 can be as rigorous or as yolo as you want. And those versions are old, too. Other ecosystems are going to take their time as well. LLVM isn't going to switch over to something AI banged out in nine days. They're going to have a long dragged out period where they run things in parallel for a while until everyone feels okay about it. If they'd even do something like that.