> even when the rust-lang/rust repository itself largely forbids vibe coding.

This policy does not seem to forbid vibe coding?

But one of the reasons they switched was because the compiler upstream for the original language they used, Zig, wouldn't accept slop contributions they wanted to make for Bun perf. What will they do when they need to try to push a slop contribution upstream to rust?

At this point they will probably just fork yet again and maintain some vibe compiler.