nix-direnv VS nix-config

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.

Power user, gvolpe has a great config that heavily customizes nvim.

I forked and customized a fairly advanced Nixos configuration that I can load from a flake on github. (Mine | Original)

I think gvolpe's nix-config repo is what u/ppen9u1n was referencing. Looks like there might be some good ideas to mine there.

I've seen this done with flakes by a NixOS power user named gvolpe. He has it configured to automatically setup each of his different systems with Home Manager, a custom UI, etc. His three different build targets are:

I think NixOS would benefit from easily accessible collection of opinionated modules/profiles/configurations with minimal set of options. Something like gnome-desktop / sway-desktop / etc. Gnome actually does pretty good job here.

The point is: currently my NixOS and Home Manager configurations have over 2k LOC total. When you search for configurations on GitHub/Google you are likely to find complex ones. For example, quick search for "nixos gnome" (Google) gives me link to NixOS Wiki (which describes only Gnome part) and blog post (https://gvolpe.com/blog/gnome3-on-nixos/) which is useful but links to really huge configuration (https://github.com/gvolpe/nix-config) that is overwhelming to any beginner.

Great example of such approach is nixos-hardware (https://github.com/NixOS/nixos-hardware) which provides one-line configuration covering hardware quirks.