Because they are still dealing with memory safety issues to this day. They ported it to rust, completely introduced a bunch of bugs, went through all that effort, just for the codebase to be not much safer.
I'm actually basing my opinion off the blog post, specifically the code. While they do get a few changes for free with the port, most of the code looks identical. And the number of unsafe statements certainly agrees.
And now they're going little by little, playing whack a mole with seg faults... My point is that the step they're at right here is the important part, and that mechanically converting the entire codebase to rust was an optional step when incrementally rewriting would've worked just as well if not better.
Being "only" 165k USD doesn't mean anything, because you didn't do a complete port, you did a port in a trench coat. If they went for the more targeted module by module approach, and did a clean and proper rewrite, LLM assisted or not, they would reach their end goal much less turbulently and without the effort of that initial frankenport.
are they dealing with more or less memory safety bugs?
for me it was already "don't run in prod" quality before. (at least after this I'm considering adding it to the CI to see how it fares.)
segfaults. I don't know. I looked at their CI and GH issues over the past few weeks. (though now GH is down so I can't do a search, but I didn't see thousands of segfaults.)
by all accounts and measures it seems it made their house of cards more manageable. despite the frankenport, no?
they already had a zig compiler fork, wanted to upstream it, but the zig maintainer(s) said it's low-effort. now they don't have to maintain their compiler fork. (or wait for the zig team to deliver the features they wish for.) no need to maintain a hybrid codebase. (though it has C++ because of the embedded JSC.)
also I have no idea what's the zig-rust FFI status, but getting over with a rewrite faster is usually better, even if you are left with non-idiomatic code.
I'm actually basing my opinion off the blog post, specifically the code. While they do get a few changes for free with the port, most of the code looks identical. And the number of unsafe statements certainly agrees.
And now they're going little by little, playing whack a mole with seg faults... My point is that the step they're at right here is the important part, and that mechanically converting the entire codebase to rust was an optional step when incrementally rewriting would've worked just as well if not better.
Being "only" 165k USD doesn't mean anything, because you didn't do a complete port, you did a port in a trench coat. If they went for the more targeted module by module approach, and did a clean and proper rewrite, LLM assisted or not, they would reach their end goal much less turbulently and without the effort of that initial frankenport.