Macos

macOS patterns

Link against macOS system frameworks

When compiling for macOS, you may need to link against system frameworks, like CoreFoundation and Security. These frameworks are shipped in a versioned SDK bundle available as pkgs.apple-sdk.

You can use the apple.sdk option to override the default SDK or remove it completely.

{ pkgs, lib, ... }:

{
  # Use a different SDK version.
  apple.sdk =
    if pkgs.stdenv.isDarwin
    then pkgs.apple-sdk_15
    else null;

  # Remove the default Apple SDK.
  # This allows you to use the system SDK at the cost of reducing reproducibility.
  # apple.sdk = null;
}

You previously had to add each framework to packages individually. For example:

{ pkgs, lib, ... }:

{
  packages = lib.optionals pkgs.stdenv.isDarwin [
    pkgs.darwin.apple_sdk.frameworks.CoreFoundation
  ];
}

This is no longer necessary. Frameworks are bundled together in a single versioned SDK.

Run x86 binaries on Apple Silicon with Rosetta

Rosetta 2 enables a Mac with Apple Silicon to transparently run x86 binaries.

Nixpkgs provides a convenient set of x86_64-darwin packages. This can come in handy for packages that don’t yet have an aarch64-compatible build or are temporarily broken on nixpkgs.

{ pkgs, lib, ... }:

let
  rosettaPkgs = pkgs.pkgsx86_64Darwin;
in {
  packages = [
    pkgs.git
  ] ++ lib.optionals (pkgs.stdenv.isDarwin && pkgs.stdenv.isAarch64) [
    rosettaPkgs.dmd
  ];
}

Compile x86 dependencies on ARM Macs via Rosetta

If you want to also compile dependencies for x86, you can add dependencies to packages:

packages = with rosettaPkgs; [
    freetds
    krb5
    openssl
];

And switch the compiler to x86:

stdenv = rosettaPkgs.stdenv;

Then, in the generated shell, you can compile software for x86, like pymssql or ibm_db.