As a NixOS user for 3 years, and a Claude user for 1+ year, I agree with you that it's an ideal fit. I've been very happy with, for example, how Claude can configure GNOME via dconf settings: tweaking those settings declaratively requires cross-domain knowledge and knowing where to dig. But Claude just knows.

But trying to set up an environment for one of those perpetually running AIs, and asking it to refactor its own configuration according to some of the high-level abstractions like dendritic flake-parts, and so on, it's just clueless and will improvise without success.

What makes Nix hard for humans also makes Nix hard for AIs: Untyped lambdas that get resolved in some implied out-of-file context means you have to know if you're looking at a NixOS module, a home-manager module, a nix-darwin module, a flake-parts module, and so on. And those modules may make assumptions about what's imported in the parent scope.

So I feel like you need to supply a rather extensive context for your project that details how you want things structured, because the ecosystem is quite fragmented, people don't fully agree on what good patterns are, and so the AI can't know what the good patterns are.

Just to be absolutely clear: I think that supplying an extensive context is absolutely worth it, and I'm having great joy and success building better Nix-based project templates, Nix-based deployment templates, etc. The amount of stable, well-made projects made by other Nix users is just amazing.

Sometimes it's nice to throw an LLM at some Nix stuff but I find that unless you're comfortable with the Nix language itself and have spent a tiny amount of time writing a derivation you might introduce quite a few footguns along the way. That said these days when I need a development flake I just point a LLM at the repo and it mostly figures out what's needed. It's just that Nix lends itself pretty well (sadly) to poking around in the dark (yes, I know about the REPL).

Wouldn’t any immutable OS accomplish this goal?

That's a solid point.

I knew my flake setup could be better but never bothered. Then one day earlier this year I threw Claude at it. Not only did it improve everything, it fixed a small bug that had been bothering me.

My confidence in doing this came from exactly what you said: If it blows everything up I can just rollback.

Have you heard of any good projects for running isolated containers in NixOS that are cheaply derived from your own NixOS config? Because that is what I want. I want a computer where I can basically install every non stock app in its own little world, where it thinks "huh, that is interesting, I seem to be the only app installed on this system".

Basically, I want to be able to run completely unverified code off of the internet on my local machine, and know that the worst thing it can possibly due is trash its own container.

I feel like NixOS, is one path toward getting to that future.

You know, I used to agree, but what I realized, is I am a software engineer, and I'm used to working in large projects with source-code as the only documentation.

And that's what's great about NixOS, you just clone nixpkgs and treat it like any other underdocumented software you might work on.

It doesn't help that there are two NixOS wikis. nixos.wiki and wiki.nixos.org.

wiki.nixos.org claims that nixos.wiki is outdated and unofficial. But both appear to receive updates, and which one wins the SEO game is a coinflip whenever i google a nixos question.

ChatGPT is very good at pulling it together to give you working code. Not on the first try, but on the third try it usually works.

A lot of us use NixOS/nix yet haven't read any documentation nor hand-written nix ourself. That's Claude Code's job.

Nix in CI seems like a really excellent match. I don’t care much about the ATproto space - but Tangled has built their CI system on Nix and I find that really compelling. CI Caching is just awful with GitHub actions - so it made me disappointed that Forgejo went that route.

Yeah, I've been using Unixey stuff for almost twenty years now (most of it Linux, and fell for the siren song of macOS for about four of them).

I liked Arch and Ubuntu and Mint and OpenSUSE well enough when I used them first, but once I actually tried NixOS it felt so obviously correct that it started to bother me that it's not the default for everything.

Being able to temporarily install things with nix-shell is game changing, and being able to trivially see what's actually installed on my computer by quickly looking at my configuration.nix is so nice. "Uninstalling" things boils down to "remove from configuration.nix and rebuild".

The automatic snapshots upon each build allows me to be a lot "braver" when playing with configurations than I was with Arch. I was always afraid to mess with video card or wifi drivers, because if I screwed something up and if I didn't know how to get back to where I was, I might be stuck reinstalling to get back to a happy state. This didn't happen that often but often enough to have made me a bit weary about futzing with boot parameters or kernel modules. Because of the automatic snapshots with NixOS, it's much easier (and more fun) to poke with the lower level stuff, because if I do break something in a way that I don't know how to fix, the worst case scenario is that I reboot and choose an older generation.

This is a bigger deal than it sounds. For example, with my current laptop, there was a weird quirk with my USB devices having to "wake up" after not being used for more than thirty seconds, meaning that I might start typing and the first three or four words wouldn't go through. After some digging, I found out that the solution is to add "usbcore.autosuspend=-1" to the kernel params. I did that and it worked.

If I had still been running Arch or Ubuntu, I probably would have just learned to put up with it, because I would have been afraid to edit kernel parameters because of the risk of breaking things in a way that I don't know how to fix.

I love NixOS. I have no desire to leave, or at least I have no desire to abandon the model. I've considered changing to GNU Guix System since I like Lisp more than I like the Nix language, but those FSF-approved distros can be a real headache for people who actually have to use their computers.

I've never really understood how version pinning is meant to work with devenv.sh or Nix more generally. If I whack a .tool-versions file in my repo, everyone who works on it can use install the exact same versions of the relevant tools using asdf. That's low tech and imperfect (and certainly not a replacement for all of Nix's features), but it works as far as it goes. None of the examples on the devenv.sh page demonstrate pinning of tools/packages to specific versions.

As best I can tell, Nix enthusiasts think that this is an XY problem and that I shouldn't want to pin individual tools/packages to arbitrary versions. But the thing is that I am a rude barbarian who very much does want to do this, however philosophically misguided it might be.

Hm. How it's different from home-manager?

Can you help me understand why devenv is needed instead of a shell like this/what is gained?

    { pkgs }:
    
    pkgs.mkShell {
      nativeBuildInputs = with pkgs; [
        # build tools
        cmake
        ninja
        gnumake
        pkg-config
      ];
    
      buildInputs = with pkgs; [
        # java
        jdk8
    
        # compilers
        gcc
        clang
        llvmPackages.libcxx
    
        # libraries
        capstone
        icu
        openssl_3
        libusb1
        libftdi
        zlib
    
        # scripting
        (python3.withPackages (ps: with ps; [
          requests
          pyelftools
        ]))
      ];
    
      # capstone headers are in include/capstone/ but blutter expects include/
      shellHook = ''
        export CPATH="${pkgs.capstone}/include/capstone:$CPATH"
        export CPLUS_INCLUDE_PATH="${pkgs.capstone}/include/capstone:$CPLUS_INCLUDE_PATH"
      '';
    }

So Discord, and quite a lot of software like this has actually two layers of updates. There's updates of the web page (which is basically writing a bunch of JS to the home directory) which NixOS does nothing to prevent, and then there's updates of the host program (i.e. Electron) which NixOS disables.

Jetbrains Toolbox is in a sort of different category with tools like Rustup, since it's a package manager of its own. If you manage your IDEs with Toolbox, then your IDE versions are "outside Nix" and not managed by Nix. It's just packaged into its own pretend FHS environment and then doesn't know anything about it being on Nix. That said, updates of Toolbox itself will need to happen through your package manager.

As a last comment, why run Docker Desktop on Linux at all? Like I understand on Windows and Mac - docker is inherently tied to Linux so the Windows/Mac apps abstract away the fact that it's running a VM and doing a bunch of port mapping and filesystem mounting under the hood so you can pretend it's not running on a VM, but on Linux I've always just installed docker straight onto the host.

No there’s a nerd who will obsessively submit the latest version of any popular software that does that to nixpkgs. Or suggest you use the flatpak.

That's not much different than other distros, because the way auto-update usually works, is it can't use root permissions or the system package manager (in any distro), so it has to install the newer version in $HOME. Once the update is installed, the system package becomes a trampoline to that.

I tried Discord, and this one seems to download some updates on first run, but the version sticks to the one from the system (0.0.127, latest is 0.0.129). So I assume it just doesn't update, or it tries to and fails.

For a personal desktop environment, I just install them normally when there's no up to date nixified option.

For some things I've vibe-coded a nix module on github that uses a scheduled github action to check for underlying app updates and then it generates a new hash and tags a release.

I've done that for claude code and cursor, which is also an opportunity to let me manage their config files from my nix config.

really good question.

right now I have bought into the Nix koolaid a bit.

I have NixOS Linux machines and then nix-darwin on my Mac.

I use Nix to install Brew and then Brew to manage casks for things like Chrome what I'm sure updates itself. So the "flake.lock" probably isn't super accurate for the apps you described.

guix would like a word

I tried fedora silverblue for a while, but the way it works is that it builds a new root fs image whenever you change the installed packages, this makes system package changes take comparatively long vs a traditional os. They suggest installing most apps via flatpak, which is okay as long as you can deal with flatpak idiosyncrasies.

I also tried fedora coreos for a vm + container host, but found the recommended method to configure the system with ignition files and one shot systemd units to be too involved for making a one off system, and it’s probably better for a cloud deployment with many identical nodes.

Same. I have a full homelab and multiple macs, can’t say I’ve written a line of real Nix code by hand.

If you’re itching to try Nix, now is the time.

Same but with kernel. What lead me to nixos: company gave me a laptop with iGPU that wasn't supported by any released linux kernel. There were patches waiting to be merged, with nixOS making an installer image that supports my machine was simple.

>I haven’t given it a shot in the LLM age

I haven't tried it in almost a year, but using Claude Code for setting up my nix config back then worked amazingly well. I've only dabbled in NixOS, and I'm very tempted to it for my workstation when I reinstall it in the next month.

Given how much Claude Code + Opus have improved in the last year, I'd give it a fighting chance to make a nice Nix config. I'll probably start setting up a spare laptop to get the base configs dialed in before switching over to it.

I'm not sure if I live in some kind of parallel world, because I never had any problems grokking Nix or NixOS. I started with this book[0] and haven't ever really been confused.

[0]: https://nixos-and-flakes.thiscute.world

LLMs are a real gamechanger for Nix, highly recommend giving it a go again.

Flakes are de facto standard at this point. Expressions are easy once you get used to them - in fact the Nix language grows on many of us, including myself, once you internalize it.

Using AI to generate Nix config is a superpower. Because the entire system is declared in a single set of config, you can basically spell cast any system you want. I one-shotted a Linux distro with custom branding for boot, installation screen, and login screen, and VPN and dev tools installed and configured by default, at a fortune 500 tech company.

Flakes are the defacto standard and you're leaving one huge point out. Flake files come with flake lock files. You cannot get lockfiles without using flakes.

Obligatory Guix plug. I've found it way easier to understand, but it has teething issues that NixOS doesn't (latest for me was a few problems with DMs). And according to an acquaintance of mine, it works reasonably well with an LLM.

You know, I'm not going to say I'm enamored with the language, but I think the Stockholm Syndrome has kicked in because I really don't hate the language so much anymore.

I mean, I'm only ever using it for configurations, and I think I'd still prefer writing Nix than YAML. I probably wouldn't like writing a full "program" with Nix, but I don't think anyone does that?

Yes. But disk space isn't exactly the most valuable resource you have as a developer/power user

Yep disk space and learning curve are the two major downsides to Nix. The former has never been a problem for me in practice, just run garbage collection once a month. The latter was a big problem, but is now mitigated for most people by LLMs.

Yes, however the space is not „used up” in a classic sense. It’s a cache, so you can give up some of it and reclaim your space. Fresh after a full cleanup it won’t take much more than a regular distro.

actually once I garbage collect, nixos actually uses up less disk space for me than other distros

Use nix.optimise.automatic = true in the config and perform nix-collect-garbage if necessary. With this it doesn't take much.

For me, it's the difference between taking your medicine a bit at a time on your own schedule or taking it all at once as an unwelcome surprise. Sure, setting up file system mounts or adding udev entries is easier to do once in Ubuntu than in NixOS, but I only need to do it the one time with NixOS. Thereafter, the config serves as both documentation and backup. For a hobby self hoster like me who occasionally shoots himself in the foot and has to rebuild a system, it is ideal. I don't know if it really saves me time, but I do know it saves my sanity.

I am no nix whiz, but it's the only OS I run outside of containers. Anything I can't easily get with my nix config I shove into a container, run it as a quadlet, and call it good.

Nix isn't really much of a hobby. It does require some learning because it's different, and front-loading the work to build your config, but after that it's amazingly reliable and easily extendable. You can keep everything up to date with a single command.

The advantages:

- Declarative code describes your system. Maybe your install + imaging flow is good enough, but there are many reasons why it's technically inferior. There's no need for imaging Nix, because it's always reproducible by default. Rollbacks are rebooting to a previous config, not a timestamped blob of snowflake state.

- It replaces whatever tools and glue you have to build your system. You don't need to worry about bootstrapping tools, or config management tools' version compatibility, or bespoke ordering of imperative steps to build the system. All the management tools are built into the system. Everything "just works" automatically.

- If you manage multiple machines the benefits are compounding.

- There are other interesting bits that are covered in the article, that you get for free just due to the nature of nix. It's good for building, and has no friction to experimenting with specific tools or environments, without polluting your system.

It's a commitment to get past the initial learning and config build, but afterwards it significantly lessens the "hobby" aspects of computer management. There are just entire classes of problems that don't exist for Nix. Either your config works, or it doesn't, and the rollback guarantee is explicit and built-in.

The configuration system is way more stable than it seems. You write it once and then pretty much never touch it again.

Imo it's the opposite. Since the system is defined in config files, an AI agent can look at live system state/errors vs. the config file and do all the work of figuring out the issue.

Also, using higher level modules like home manager makes things more declarative and less fiddly since someone else is maintaining the lower level.

Maybe nix is a downgrade for what you do. But I loved nix so much that I also migrated to nix on macOS (nix-darwin). No more homebrew.

nixos updates tend to be a lot less eventful than others distro, in fact the way it largely prevent system borking when updating, is spiritually freeing.

Already exists, although I don’t know how well maintained it is: https://github.com/henrysipp/omarchy-nix

Personally, I don’t see the need for this with NixOS. Setting aside the fact that Omarchy is way too opinionated (Basecamp installed by default?), NixOS is already quite composable, so you can easily build a well-formed experience out of isolated NixOS modules.

What would the in between be?