This allows people to more easily use the upstream nixcrpkgs if they
wish by fetching the macos sdk separately (such as from a private s3
bucket), and then passing it as an argument to nixcrpkgs.
For good measure, this also makes it possible to pass in 'nixpkgs' so
that people who are using this from nix can avoid an extra nixpkgs
evaluation.
I retained the previous macos_sdk behavior by default, so this should be a backwards compatible change.
This allows people to more easily use the upstream nixcrpkgs if they wish by fetching the macos sdk separately (such as from a private s3 bucket), and then passing it as an argument to nixcrpkgs.
For good measure, this also makes it possible to pass in 'nixpkgs' so that people who are using this from nix can avoid an extra nixpkgs evaluation.
I retained the previous macos_sdk behavior by default, so this should be a backwards compatible change.