There are various useful darwin specific commands in darwin.*_cmds packages, like `traceroute`, `xcrun`, `cp`, `codesign`, etc. I've seen people asking in [discourse][1] and matrix about how to get darwin specific commands, including darwin.* will make them more discoverable. [1]: https://discourse.nixos.org/t/osx-sdk-is-mig-mach-interface-generator-packaged/56174/2
