dream2nix VS nix-direnv

(I'm on the flox team) we'd love to support that and it's something we've talked about! We already support auto-generation for some languages like Rust because they have a lockfile (e.g. Cargo.lock), but it's a bit trickier for a requirements.txt. We hope at some point to contribute to/integrate with upstream efforts like dream2nix which have auto-generation as their goal

How about dream2nix? I like to use the nix way, but there are many third nix ways

I'm not 100% sure, but looking at the docs [here](https://nix-community.github.io/dream2nix/subsystems/node.html#granular-pure-default) and the implementation [here](https://github.com/nix-community/dream2nix/tree/main/src/subsystems/nodejs/builders/granular-nodejs) it seems as it builds dependencies separately and symlinks (see `install-deps.py` those into a `node_modules` tree. I don't know much about Yarn's PNP (was doing more backend/devex last few years), but it sounds vaguely similar in that each package should be built once as a separate derivation and then symlinked to a big `node_modules`-as-a-symlink-tree derivation?

How are you building your NodeJS project with Nix right now? Recently I spot a new abstraction, it looks good but I havn't tried it yet: https://github.com/nix-community/dream2nix

dream2nix is a great package, that makes a nix-derivation out of node project with the minimal flake

The DavHau/dream2nix project aims to be a generic solution for this issue by splitting the problem into specific stages, each of which can be configured individually (e.g., changing the level of purity)

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.