Questions about profiles/generations on MacOS

[ryanmsnyder]

A couple of questions relating to profiles/generations on MacOS:

1. How do I rollback to a previous generation? Do I need to use ./result/sw/bin/darwin-rebuild?

2. This question is probably more geared toward nix/nix-darwin in general but why aren't ~/.nix-profile/Applications and /Applications/Nix Apps always in step with each other? For example, when I:

• run nix run .#build-switch
• remove a package from the config
• run nix run .#build-switch again

that package remains in ~/.nix-profile/Applications but is removed from /Applications/Nix Apps. I would expect it to be removed in ~/.nix-profile/Applications as well because launchers such as Spotlight and Raycast still pick up the removed package/app since it's still in ~/.nix-profile/Applications.

The second question may be completely unrelated to profiles/generations but I'm a nix noob and can't figure out why applications aren't being removed from ~/.nix-profile/Applications when I remove them from my config.

Thank you for config. It's helping me learn a lot about nix.

[dustinlyons]

Hi @ryanmsnyder! Thanks for giving this project a try. Glad it's helping you learn Nix. I'm still always learning it ;)

In re: to your questions:

How do I rollback to a previous generation? Do I need to use ./result/sw/bin/darwin-rebuild?

I added a new Nix app to the project for rollback. Check it out here:
https://github.com/dustinlyons/nixos-config/blob/main/templates/starter/apps/aarch64-darwin/rollback

If you just want to run the underlying commands and not add this into your configuration (assuming you already used the starter template), it's:

/run/current-system/sw/bin/darwin-rebuild --rollback

This question is probably more geared toward nix/nix-darwin in general but why aren't ~/.nix-profile/Applications and /Applications/Nix Apps always in step with each other?

I don't have a quick answer for you. It depends on how you're installing the application. I know with the homwbrew module for nix-darwin, some apps aren't uninstalled automatically:

https://daiderd.com/nix-darwin/manual/index.html#opt-homebrew.masApps

I would expect the symlinks to be cleaned up, however. You should be able to manually clean it up yourself, however. That may be a workaround until you get a better answer. I would check with the nix-darwin folks.

[ryanmsnyder]

Thank you for your response @dustinlyons. I'm actually not using homebrew to install the applications. I'm just using home-manager.users.${user}.home.packages.

One thing I just noticed in the config is that modules/shared/packages.nix is getting called in both:

• modules/darwin/home-manager.nix in home-manager.users.${user}.home.packages (user's profile)
• hosts/darwin/default.nix in environment.systemPackages (system-wide)

Is this intentional? That explains why the applications are getting symlinked in ~/.nix-profile/Applications as well as /Applications/Nix Apps.

[ryanmsnyder]

Also, I've noticed the symlink is being cleaned up from~/.nix-profile/Applications when I remove a package/app from being installed via home-manager. Likewise with executables in ~/.nix-profile/bin.

Finder/ForkLift was still showing the removed package in ~/.nix-profile/Applications until I restarted them. I guess symlinks aren't automatically refreshed in Finder/ForkLift even if you navigate out of the directory containing the symlinks and then navigate back into it - they have to be relaunched/restarted.