linux-builder: make compatible with cross-arch builder package

Before this commit, aarch64 users building the following configuration
would end up with an aarch64-linux builder, while after it, they get the
x86_64-linux builder they expect:
```nix
 nix.linux-builder = {
  enable = true;
  package = pkgs.darwin.linux-builder-x86_64;
};
```

Before, in order to get an x86_64-linux builder, they would have needed
to use this configuration instead:
```nix
 nix.linux-builder = {
  enable = true;
  config.nixpkgs.hostPlatform = "x86_64-linux";
  systems = ["x86_64-linux"];
};
```

The reason for this is that the linux-builder module calls `override` on
the package option, and the `linux-builder-x86_64` package is also
defined using override:
```nix
linux-builder-x86_64 = linux-builder.override {
  modules = [ { nixpkgs.hostPlatform = "x86_64-linux"; } ];
};
```

The module was effectively discarding the `nixpkgs.hostPlatform` option.

Example issue: https://github.com/NixOS/nixpkgs/issues/313784

0 files changed, 0 insertions, 0 deletions