May 9, 2026
Rust never sleeps, comments never chill
Bun ported to Rust in 6 days
A giant app got rebuilt in under a week, and the crowd instantly asked: at what cost
TLDR: Bun’s creator says a huge rewrite into Rust happened in just 6 days and still passed nearly all existing checks, a big deal because it could mean fewer crashes and easier maintenance. Commenters were torn between amazement, curiosity about how much AI help it took, and very online source-link nitpicking.
The internet loves a miracle story, and this one came in hot: Bun, a fast app-building tool, was reportedly ported to Rust in just 6 days, with 99.8% of its old tests still passing on one Linux setup. For non-coders, that’s basically like rebuilding a sports car’s engine in less than a week and having almost every dashboard light still come up green. The creator says the big appeal is simple: fewer crashes, fewer leaks, fewer late-night panic fixes. In other words, less chaos.
But the real show was the crowd reaction, and it split instantly into awe, suspicion, and petty internet housekeeping. One camp was basically screaming, “Wait, six days?!” and immediately wanted to know how much artificial intelligence help was used, with people obsessing over the unseen price tag in computing power and tokens. Another mini-drama spun up over link etiquette: one commenter gently pointed to an earlier thread, while a moderator stepped in with a hall-monitor energy reminder to post the original source instead of an alternate mirror. Yes, even in a story about a near-million-line rewrite, the comments still found time for source-link drama.
The funniest part is that nobody seems able to decide whether this is a triumph of modern tools, a flex by an exhausted developer, or the opening shot in another endless programming language feud. Either way, the comments made one thing clear: the rewrite is impressive, but the real entertainment is watching the internet argue over how impressed it’s allowed to be.
Key Points
- •Bun’s creator said a Rust rewrite was completed in six days.
- •The post reports that 99.8% of Bun’s pre-existing test suite passes on Linux x64 glibc.
- •The rewrite is described as largely keeping the same codebase while gaining compiler-enforced lifetimes and explicit unsafe sections.
- •The stated motivation was to reduce memory leaks, crashes, and stability issues through stronger language-level safety tools.
- •The author said the effort involved about 960,000 lines of code and that a future blog post will cover benchmarks, memory usage, maintainability, and the rewrite process.