Merge pull request #260770 from hercules-ci/darwin-builder-observable

You may make any other changes to your VM in this attribute set. For example,

you could enable Docker or X11 forwarding to your Darwin host.

## Troubleshooting the generated configuration {#sec-darwin-builder-troubleshoot}

The `linux-builder` package exposes the attributes `nixosConfig` and `nixosOptions` that allow you to inspect the generated NixOS configuration in the `nix repl`. For example:

```

$ nix repl --file ~/src/nixpkgs --argstr system aarch64-darwin

nix-repl> darwin.linux-builder.nixosConfig.nix.package

«derivation /nix/store/...-nix-2.17.0.drv»

nix-repl> :p darwin.linux-builder.nixosOptions.virtualisation.memorySize.definitionsWithLocations

[ { file = "/home/user/src/nixpkgs/nixos/modules/profiles/macos-builder.nix"; value = 3072; } ]

```

{ config, lib, ... }:

{ config, lib, options, ... }:

let

  keysDirectory = "/var/keys";

      in

      script.overrideAttrs (old: {

        pos = __curPos; # sets meta.position to point here; see script binding above for package definition

        meta = (old.meta or { }) // {

          platforms = lib.platforms.darwin;

        };

        passthru = (old.passthru or { }) // {

          # Let users in the repl inspect the config

          nixosConfig = config;

          nixosOptions = options;

        };

      });

    system = {