I'm opening a tracking issue for updating the Darwin bootstrap files to document pending changes, and to see if/when we have enough reasons to perform an update.

The last update was in 2021 as part of #105026. I've been told updates to bootstrap-files are supposed to be rare, and there should be good rationale. Once we have that, plus some thumbs up from @NixOS/darwin-maintainers, we should be able to find help getting tarballs.nixos.org updated via #infra:nixos.org.

Currently pending changes:

• stdenvBootstrapTools: native aarch64-darwin build #202347
  This PR changed the structure of the bootstrap files. Currently, there is the main bootstrap-tools archive, plus some separate executables required to unpack it (sh, bzip2, mkdir, cpio). The new structure is just an archive, and uses the builtin Nix support for .nar.xz unpacking. The PR contains more rationale, plus there's an example commit.

• apple-m1 compiler optimisations for aarch64-darwin? #166401
  Maybe(?) update LLVM and change arch flags for Apple Silicon.

• Anything else?

Reasons to delay:

• With only the first one above currently on master, the pending changes do not significantly affect the resulting stdenv.

Reasons to move forward:

• Maybe we want to resolve the discrepancy in structure (between the bootstrap-tools we build and the bootstrap-tools we fetch) before 23.05?