https://ziggit.dev/t/bun-s-zig-fork-got-4x-faster-compilatio...

> An example of this is the changes to type resolution which happened in the 0.16.0 release cycle—these didn’t affect users too much, but had big implications for the compiler implementation. Before those changes, the compiler’s behavior was often highly dependent on the order in which types and declarations were semantically analyzed by the compiler. Some orders might result in successful compilation, while others give compile errors. Single-threaded semantic analysis prevented these bugs from causing user-facing non-determinism. The rewritten type resolution semantics were designed to avoid these issues, but Bun’s Zig fork does not incorporate the changes (and has not otherwise solved the design problems), which means their parallelized semantic analysis implementation will exhibit non-deterministic behavior. That’s pretty much a non-starter for most serious developers: you don’t want your compilation to randomly fail with a nonsense error 30% of the time.

There is a reason why, zig is upholding the quality and they hate it.