May 9, 2026
Rust never sleeps
Bun's experimental Rust rewrite hits 99.8% test compatibility on Linux x64 glibc
Bun’s big code makeover is almost flawless — and the comments are already fighting about what it means
TLDR: Bun says its big rewrite is already passing 99.8% of old checks on Linux, a strong sign the risky rebuild may actually work. But the comments quickly spiraled into a bigger fight over AI coding, whether this is real progress, and if plain English is becoming the new way to write software.
Bun creator Jarred Sumner dropped a deceptively small post with a very loud message: the project’s experimental rewrite now gets 99.8% of its old tests to pass on one major Linux setup. In plain English: the team is trying to rebuild a popular speed-focused JavaScript tool in a different programming language, and so far, it’s going shockingly smoothly. That tiny missing 0.2%? Naturally, the internet smelled drama anyway.
The comments instantly turned this from a developer update into a full-on culture war about how software gets made now. One camp was impressed by the sheer pace, with people framing it as proof that modern AI-assisted coding and huge amounts of computing power are changing the game fast. Another camp hit the brakes hard, warning that people keep calling every new change “progress,” when sometimes it’s just… change. That sparked the classic online split: is this exciting innovation, or are people getting way too breathless too fast?
Then came the extra spicy side plot: one commenter declared the industry is drifting toward “English as the programming language,” basically saying developers may spend more time describing what they want than hand-writing every detail. Some loved that idea. Others clearly found it cursed. There weren’t many obvious jokes in the thread, but the mood had that familiar internet flavor of equal parts awe, skepticism, and nerd panic. Bun posted a win; the crowd turned it into a referendum on the future of coding itself.
Key Points
- •Jarred Sumner posted that 99.8% of Bun’s pre-existing test suite passes in its Rust rewrite.
- •The reported result is specifically for the Linux x64 glibc environment.
- •The test result is measured against Bun’s existing test suite rather than a newly described benchmark.
- •The article presents the update as a short X post without added technical breakdown or release details.
- •Sumner’s profile in the article identifies him as building Bun at Anthropic and formerly being associated with Stripe and the Thiel Fellowship.