Emphasis on the FOSS project. The v1.4 mentioned is not (yet?) open source, Claude Code is essentially using a proprietary fork, was GP's point.
It's a canary releasing directly from main: https://github.com/oven-sh/bun
We have run it in production for a month: https://www.prisma.io/blog/bun-rust-rewrite-prisma-compute
And GP is full of shit as the main branch is the v1.4.0. it is not "released" yet as it is not finished. It is available as canary version.
You can install it now we with bun upgrade —-canary it something along those lines.