I think where Nix shines isn’t “one laptop every 6 years” but when your environment needs to be shared or recreated: multiple machines, a team, or a project with nasty native deps. At that point, nix-darwin + dev shells becomes infrastructure, not a hobby. You don’t have to go all-in on “my whole Mac is Nix” either: keep GUI apps and casual tools imperative, and treat Nix as the source of truth for the stuff that actually blocks you from doing work. That hybrid model matches what the article hints at and tends to give you most of the upside without turning your personal laptop into a second job.
If I make a git repo, place '~/.config/newsapp.conf' in there and then symlink it back to '~/.config/', if NewsApp introduces a new variable in its settings I am immediately aware because Git will complain about being dirty. However, Nix will happily just nuke that .conf and rebuild whatever is in your configuration, without letting you know about state. Which is ultimately bad for reproducibility. It's a huge blind spot in Nix.
I'd like to add the third thing, which is just iteration. It's very tricky to maintain advanced workflows even locally. I'd guess many won't even try to compose things that could work in combination (often self-hosted services), when they know they can't reliably maintain those environments.
But I think just in fairness, the comparison here for flakes should be to Homebrew bundles. My packages are managed in a bundle: https://github.com/Julian/dotfiles/blob/main/Brewfile and then locked by a lockfile: https://github.com/Julian/dotfiles/blob/main/Brewfile.lock.j... and installing is just `brew bundle install`. All native Homebrew functionality. In practice I have never had an issue with non-reproducible builds across my machines (partly because the tendency on macOS is to run the latest versions of things and stay up to date).
(But again I do find nix-darwin interesting to try for other reasons.)
The bundler integration for nix-darwin actually just bakes tightly-controlled Brewfiles. It’s still worthwhile though, since part of the “tightly-controlled” means better cleanup when you remove things.
> The consequence is me, spending a few hours debugging my environment instead of writing code.
But then I also see this:
> I’ve spent a lot of time recently moving my entire workflow into a declarative system using nix.
I can see how this can be beneficial for someone who switches systems very often, reinstalls their OS from scratch very often, or just derives a lot of pleasure/peace of mind knowing that their dev env is immutable.
I change computers once every 6 years or so, maybe more. To me this looks like exchanging a couple (hypothetical) hours of debugging 6 years in the future by tens of (guaranteed) hours trying to climb up the nix learning cliff.
I am happy that it works for the author though, and knowing that it's possible is good in case my particular development circumstances change.
The only way you get positive ROI from Nix is either you enjoy the journey, or you use it to do more than just managing a single computer: you manage a fleet, you build thin application container images, you bundle all your software, you have devshells, repeatable tests and deploys, etc. It's the same tool for all of them.
Nix is a wonderful technology. But I would not argue it is practical if you can afford "just fix it when it breaks". A nix setup more/less requires you to pay all the cost up front.
I appreciate putting in the effort now so that I don't have to later for stuff like declarative dev environments. It's really nice to not have to copy-and-paste installation instructions from a README. -- I did like the point: until you've felt what a comfortable design is, you cannot imagine it.
For me Nix/NixOS is by far the most effective for deploying servers, development VMs, etc. I do this regularly, so it pays off - I have a familiar environment completely set up in minutes. Another place it pays off, even on macOS, is for development environments, especially if you have to pull in a lot of native dependencies (which can happen in mixed Python + C++ projects, mixed Rust + C/C++ projects, etc.).
Nix shines in all difficult cases, like setting up complex cross-compilation environments, building for old glibc versions, etc. You set it up once and then it's really easy for yourself and other project contributors to get the same build environment.
Like any tool, a good engineer knows when to apply it.
It's also about peace of mind like you said. Before nix I sometimes felt anxiety installing or upgrading certain things on my computer. "Will this upgrade break stuff?" - and often it did and I'd have to spend the next few hours debugging. With nix I don't worry about any of that anymore.
Even for things like trying out a new shell you can temporarily move the dotfiles somewhere and restore them back and it still takes less time than converting everything to Nix.
A simple UNIX script or PowerShell utility takes care of it.
None of the ones I have used during the last decades has ever grown to more than like 20 lines of code, minus comments.
I think the closest mainstream UX for "you can try out this program without having to install it" is running a Docker image.
:) I'd say Nix is second best at everything related to packages.
If you just want a throwaway VM, it's straightforward to create one through the UI cloud console. Whereas, terraform is nevertheless still a useful tool to use to manage VMs.
For stuff like installing development dependencies.. it's maybe not difficult to copy-and-paste instructions from a readme, but solutions like devcontainers or Nix's development shells can be useful even if costing more overhead.
yes, it sounds like it's not worth it for you -- you will have to spend a significant amount of time converting your system to do things "the nix way". you can try to do this incrementally, but it's a time sink, and really easy to get stuck bikeshedding instead of doing work.
for me, it feels like a near equal trade-off between debugging nix, or debugging some random env issues that pop up. i know nix, claude code "knows" nix, a lot of other people online know nix. random env issues are random, and yield worse results on google, and frankly are much more frustrating to the point i would rather spend more time with nix than deal with them. maybe a very weird view.
I would recommend it only if this type of thing naturally interests you. I can't imagine powering through the initial learning curve if it felt like a frustrating chore.
That said, if having (most of) your machine defined declaratively in a git repository sounds exciting/useful/comfy, then I would encourage you to give it a try. You can start small by just configuring a few programs or options and see how you like it.
I wrote more about my experience here where I also link to my configs: https://bryce.is/writing/code/fully-nix-pilled
When i install a fresh macos i have two commands to run - install nix using the determinate systems installer, then apply my nix config.
It's not quite as streamlined as nixos but good enough.
My biggest remaining pain point is dev envs - i've been leaning into adding a flake in each project, so for example i have a single project that's written in scala 2.13, when i cd into that project dir, the correct jvm version, sbt, intellij etc are installed, some useful env vars and shell aliases etc. - that's all great (i haven't felt the need to adopt denenv.sh or flox yet) but i do find myself wanting a devcontainer sandbox workflow more often these days (blame cli coding "agents"), i lean on vscode for that rather than nix so far. In python (where i spend a lot more time) uv loses a lot of value in nix and i don't like that.
I also really wanted to like the declarative homebrew configuration but it also often didn’t work as expected for some configurations and had a lot of leaky abstractions that straight up just broke sometimes.
If I ever go back to managing my Mac with nix I would probably just do a home-manager setup and just install most of the applications imperatively.
Given this was using an intel based machine around the time when the switch to arm came so a lot of breakage also stemmed from that.
I still use nix to handle my homelab.
My setup up on my Mac is as follows:
- Orbstack
- NixOS machine run in orbstack
- My whole dev environment is run from this container and is very transportable
- GUI apps are installed on my Mac using the App Store or homebrew etc. but I try to reduce the amount of installed applications
- if I have to install something that I don’t want to install but have to, I try to do it in a UTM machine.
$HOME/bin
That being said, we used NixOS images to boot several Windows PCs of my friends into RAM to play Halo 3 multiplayer split-screen. Most of my friends were mainly confused why they could play with any gamepad they had in their shelf. They also left the event with no permanent changes to their PCs.
There's of course Fedora Silverblue / Fedora Bootc with https://universal-blue.org/ and https://blue-build.org/ being good examples.
Recent developments have seen the creation of bootc images for non-Fedora distros too, and at this point I've seen quite a few cool arch-bootc custom images, completely customized to the author's desires. See: https://github.com/bootcrew/, https://github.com/tartaria-dev/tartaria
Nix may not be the tech that replaces everything, but at the very least it is and has been an important exploration vehicle for declarative configuration, immutable systems, etc.
This is just procrastination.
I still believe something like nix is the future of building software, I'm just not sure it'll be nix itself.