Buz – A fork of Bun using modern Zig, with sub-1s incremental builds

Re:Buz – A fork of Bun using modern Zig, with sub-1s increme... by GuB-42 on Friday July 24, 2026 @01:25PM (#49038924)

GP is talking about the fork of the Zig compiler, not the rewrite of Bun into Rust.

Anthropic submitted to patch the Zig compiler to improve Bun compilation times, it was rejected. One reason it was rejected is that it contained AI-generated code, which is against the community guidelines, but more importantly, it would have been rejected regardless of AI use. They claimed a 4x improvement, something like going from 2 minutes to 30 seconds, but, according to the Zig team, it made compilation non-deterministic, and missed on the real improvement they worked on, which was sub-1s incremental builds.

"Buz" shows that the fork submitted by Anthropic wasn't needed as Bun can now compile under 1s (incrementally), which is much better than the 30s they achieved with their patch.

It is likely that this rejection, especially the "no AI" aspect of it encouraged Anthropic to move away from Zig.

[ Parent | on HN ]

Re:Buz – A fork of Bun using modern Zig, with sub-1s increme... by dtj1123 on Friday July 24, 2026 @04:06PM (#49040981)

Yep, on rereading my comment I totally failed to make this clear. Cheers.

[ Parent | on HN ]

Re:Buz – A fork of Bun using modern Zig, with sub-1s increme... by dminik on Friday July 24, 2026 @01:30PM (#49038994)

Is there anything suggesting that Bun even attempted to submit their Zig patches? As far as I know, they were stuck 2 versions behind. With the amount of changes and Zig already working on incremental I'm not sure what the point would have been.

[ Parent | on HN ]

Re:Buz – A fork of Bun using modern Zig, with sub-1s increme... by kristoff_it on Friday July 24, 2026 @02:57PM (#49040173)

Yes it was never attempted, the whole communication on social media about the AI policy was completely detached from the reality of the engineering work being done on either side.

[ Parent | on HN ]