That GitHub search only covers the main branch, not the not-yet-merged Rust rewrite; the only Rust code in there is tests for Rust FFI (so that people can write native extension modules for Bun in Rust if they want to).

The rewrite's in https://github.com/oven-sh/bun/tree/claude/phase-a-port. By running the following command on it, I count about 14,000 unsafe blocks:

  rg --stats -g '*.rs' 'unsafe \{|unsafe impl|#!?\[unsafe\('

I have not had time to look at the code myself, but from when this was initially posted to Reddit, IIRC it had around a thousand global mutable variables, which are unsafe to access.

I am very curious what the numbers are once the test suite passes and after a few passes of reducing the amount of unsafe.