There's so much good stuff in this post.
Can't help to think of a recent HN post about most AI-generated projects being abandoned within months. Why?
Because value of a project is not in the code produced. It's in the amount of battle-testing that code has seen.
Battle-tested, mature code > fresh rewrite.
Existing Zig codebase has seen X amount of battle-testing. Rust rewrite: 0 (except -I'm assuming- passing test suites). Also:
"this was a port to unsafe Rust, allowing a literal file-by-file migration to minimize risk"
How is that better than the Zig codebase you started with?
Now if that's further migrated to safe Rust, put into production & gathered feedback from lots of users, yes then you have something. As it is, the impressive bit is do such a big rewrite & result seems to work ok. Are Bun users happy with this?
To me it reads like Bun was forked. Will the Zig version survive? Will the Rust one? Both? All options ok.
Edit: and fwiw, I don't think Zig community should get triggered on any of this. It says nothing about how suitable Zig is or isn't for project xyz, and Zig community is big enough to carry their own project & applications besides Bun.