[Enhancement] Don't create "/Applications/Nix Apps" unless necessary

[wzxu]

Due to various reasons such as Spotlight discoverability and the zapping mechanism, I find Homebrew Cask to be a better way of managing GUI apps, so I only let Nix handle CLI apps. However, the symlink "/Applications/Nix Apps" always gets created even though there's no need for it and the target directory is empty.

I found the file that's responsible for creating it here, and, with my limited Nix knowledge, I tried to set system.activationScripts.applications.enable = false or system.activationScripts.applications.text = "" in my nix.flake, neither of which worked of course.

So I'm wondering if it's possible some change is made in nix-darwin so that this symlink is only created if there exists at least one GUI app installed by Nix?

[sdht0]

This seems to be working for me:

{
  lib,
  ...
}:
{
  config = {
    system.activationScripts.applications.text = lib.mkForce "";
  };
}

[wzxu]

@sdht0 It works. Thanks for the hint!

I'll leave the ticket open in case there's some improvement to be made here.
Or the maintainers can close it as "won't fix" if they deem so.

[bfeitknecht]

How exactly does this work? Does this need to be added to flake.nix with the nix-darwin template? If so, where? Thank you for the help.

[wzxu]

@bfeitknecht Yes in flake.nix or configuration.nix.

For example:

{ pkgs, inputs, ... }:

{
  services.nix-daemon.enable = true;

  nix = {
    registry.nixpkgs.flake = inputs.nixpkgs;
    nixPath = [ "nixpkgs=${inputs.nixpkgs}" ];
    settings.experimental-features = [ "nix-command" "flakes" ];
  };
}

Would become:

{ lib, pkgs, inputs, ... }:

{
  services.nix-daemon.enable = true;

  nix = {
    registry.nixpkgs.flake = inputs.nixpkgs;
    nixPath = [ "nixpkgs=${inputs.nixpkgs}" ];
    settings.experimental-features = [ "nix-command" "flakes" ];
  };

  system.activationScripts.applications.text = lib.mkForce "";
}

[emilazy]

I really suggest not monkey‐patching activation scripts like this, we can’t really support it and it could lead to unintended problems.

I’d be happy to review a PR to modules/system/applications.nix to fix this. It would just need to check if ${cfg.build.applications}/Applications is empty and remove the link (if present) rather than creating it.