nix-direnv VS flake-utils-plus

BTW: I personally use direnv with nix-direnv. This basically works by setting your shell with proper tooling when you enter the directory.

I'm not sure what you mean by nix env, maybe you are referring to nix-direnv?

Although currently I'm using direnv + nix-direnv. Keep in mind that direnv has builtin nix support which is very basic and doesn't do any caching. So you still needs this add-on to preserve roots.

I distinguish between system level things and user level things, even though I don't really have different users on my machine. I install the bare minimum number of packages + a lot of different drivers in the configuration.nix, and desktop and editor related things in HM. For development environment, I have environment per project using mkShell and https://github.com/nix-community/nix-direnv, which allows you to switch to the specific environment once you cd into the directory. (Although I do have python installed globally with some commonly used packages such as numpy, so I can just start python and write something when I need to, without creating an environment)

I further make my software projects so that when I click a link I go into an environment pre-loaded with their dependencies so dropping in/out of projects is always frictionless. I do this with the reproducibility guarantees of nix, along with glue like nix-direnv and envrc-mode to direnv.

(I also use nix-direnv)

direnv

Personally I use nix-direnv. No longer the need to run nix develop or nix-shell. By setting up a .envrc with either use nix or use flake it will automatically install all the packages from default/shell.nix or flake.nix

Direnv is installed using the nix-direnv installation instructions under "Via configuration.nix in NixOS". I read some recommendations that envrc.el is a better alternative then direnv.el, and after some testing I have to agree. (envrc-global-mode) is enabled in my config. This works perfectly with a normal emacs instance.

You don't need channels to use nix-shell or nix-env. You can generate the Nix path and registry from your flake inputs. flake-utils-plus makes this easy with nix.generateRegistryFromInputs and nix.generateNixPathFromInputs.

Use flake-utils-plus to easily define multiple systems in flake.nix.and then use the --target-host flag of nixos-rebuild to deploy it remotely.

If you're trying to handle multiple systems with one config a flake is a significantly better option. I would personally recommend looking at flake-utils-plus and specifically this example config.

I looked at some past threads / examples and saw people recommend flake-utils-plus, but after reading the examples I don't understand how I would get home-manager on Darwin or Ubuntu.

Depending on your specific needs, the channelsConfig (modify arguments passed to Nixpkgs) and overlay tooling in flake-utils-plus may be adequate: https://github.com/gytis-ivaskevicius/flake-utils-plus/tree/...

For flakes you don't have to set up everything manually there are helper libraries, I use flake-utils-plus.

Converting to flakes is not that hard if you use a good library. The documentation is other people's configs, really.

Neat! I've been using flake-utils-plus's implementation until now. https://github.com/gytis-ivaskevicius/flake-utils-plus/blob/master/lib/repl.nix

I use flake-utils-plus based configuration to apply patches on top of nixpkgs where overlays don't suffice.