by pxc | 2025-08-21 18:14:02+00:00
> Systemd and Kubernetes are examples of things that do a lot of re-implementation but are mostly better than the previous.

I feel the same way about systemd, and I'll take your word for it with respect to Kubernetes. :)

> "this really hard problem will be solved once we just re-implement everything inside our new system" [...] rarely works

Yes. 100%. And this is definitely characteristic of Nix's ambition in some ways as well as some of the most painful experiences users have with it.

> you really need a degree of pragmatism to interact with the real world

Nix is in fact founded on a huge pragmatic compromise: instead of beginning with a new operating system, or a new executable format with a new linker, or even a new basic build system (a la autotools or make)! Instead of doing any of those things, Nix's design manages to bring insights and features from programming language design (various functional programming principles and, crucially, memoization and garbage collection) to build systems and package management tools, on top of existing (even aging) operating systems and toolchains.

I would also contend that the Nixpkgs codebase is a treasure, encoding how to build, run, and manage an astonishing number of apps (over 120,000 packages now) and services (I'd guess at least 1,000; there are some 20,000 configuration options built into NixOS). I think this does to some extent demonstrate the viability of getting a wide variety of software to play nice with Nix's commitments.

Finally, and it seems you might not be aware of this, but there are ways within Nix to relax the normal constraints! And of course you can also use Nix in various ways without letting Nix run the show.[0] (I'm happy to chat about this. My team, for instance, uses Nix to power Python development environments for AWS Lambdas without putting Nix in charge of the entire build process.)

However:

- fully leveraging Nix's benefits requires fitting within certain constraints - the Nix community, culturally, does not show much interest in relaxing those constraints even when possible[1], but there is more and more work going on in this area in recent years[2][3] and some high-profile examples/guides of successful gradual adoption[4] - the Node ecosystem's habit of expecting arbitrary network access at build time goes against one of the main constraints that Nix commits to by default, and *this indeed often makes packaging Node projects "properly" with Nix very painful* - Python packaging is a mess and Nix does help IME, but getting there can be painful

Maybe if you decide to play with Nix again, or you encounter it on a future personal or professional project, you can remember this and look for ways to embrace the "heretical" approach. It's more viable and more popular than ever :)

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0: https://zimbatm.com/notes/nix-packaging-the-heretic-way ; see also the community discussion of the post here: https://discourse.nixos.org/t/nix-packaging-the-heretic-way/...

1: See Graham Christensen's 2022 NixCon talk about this here. One such constraint he discusses relaxing, build-time sandboxing, is especially useful for troublesome cases some Node projects: https://av.tib.eu/media/61011

2: See also Tom Bereknyei's NixCon talk from the same year; the last segment of it is representative of increasing interest among technical leaders in the Nix community on better enabling and guiding gradual adoption: https://youtu.be/2iugHjtWqIY?t=830

3: Towards enabling gradual adoption for the most all-or-nothing part of the Nix ecosystem, NixOS, a talk by Pierre Penninckx from 2024: https://youtu.be/CP0hR6w1csc

4: One good example of this is Mitchell Hashimoto's blog posts on using Nix with Dockerfiles, as opposed to the purist's approach of packaging your whole environment via Nix and then streaming the Nix packages to a Docker image using a Nix library like `dockerTools` from Nixpkgs: https://mitchellh.com/writing/nix-with-dockerfiles