NixOS can’t configure desktop environments, such as Gnome and KDE.

The issue here from my point of view is rather that

1. Desktop environments expect to be configured by the user through their graphical interface for that user only (Nix doesn’t touch user configuration) and
2. DEs tend to mix configuration with state (especially Plasma).

Both of these make it close to impossible to configure DEs as Nix configures other services and programs.

For clarification for readers, Nix does allow you to install these environments and associated display managers as in making them available to the user.

But in server environments, tools such as Ansible are orders of magnitudes more comprehensive to everyone who understands the Linux basics. NixOS is therefore dominant in neither desktop nor server environments, but it’s a neat academic project.

Having used Ansible superficially for an Arch server, I disagree. The beauty of Nix isn’t (only) that what you declare in your configuration is available to the system. It is the guarantee that it’s only these declarations and their dependencies are active. E.g. when you remove something from your systemPackages list, it’s no longer installed, you don’t need to uninstall it explicitly. Applying a configuration to a system will lead to a known state (if not using flakes, this doesn’t apply to derivation versions though). The same cannot be said for applying an Ansible playbook to a system because it’s rather additive.

Its nature also makes it a good candidate for development as you can enter well-defined environments regarding available libraries. That’s why it’s also a good contender there.

I failed to find sources for what I’m about to say, but there was a point where the NixOS stable branch… broke. I’m not sure what went down, but I think that a manual merge train messed smth up. If that’s correct, then NixOS is less stable than Debian.

First off, I haven’t heard about the issue. I agree this is something that shouldn’t happen, however I’m also having a bit of a hard time understanding what this would mean. You can always boot your old generations and wait for upstream nixpkgs to be fixed; plus, if using flakes, you can also go back to a pinned version of nixpkgs on your current channel. At least that’s my understanding. Myself I have never had the need.

There’s also the situation where they store the entire package store in Amazon S3 because someone else paid for it. That someone disappeared, and they expect the community to stem the costs now. If they don’t pay up, NixOS stability is once again dead.

The situation isn’t great, I agree, however it should be noted that this concerns the binary cache that keeps compiled copies of all revisions of all packages. Even if it was gone tomorrow, one could still use NixOS as a source based distribution, which would of course require the original sources still being online. The thread is not about the nixpkgs repository — it is fully defined by the Github repository — but about the (arguably very important) binary cache. It would not lead to NixOS being unstable.

I feel like the tooling is all over the place. There are many ways to do one thing, and you never know what’s the right thing to do.

I agree on this point, especially stuff like nix-shell vs nix shell doesn’t help, and the language feels a bit opaque. But I guess that’s the logical conclusion when your configuration is code — the former is usually assumed to be a fixed pattern while actual code leaves the decision how to do something to yourself. I have thought about the issue myself, but I don’t know how it would actually be solved. Though if you don’t deviate from the very defaults, it feels like a classic configuration (if that makes sense).

Overall a poor experience.

It was the extreme opposite for me, I switched my main machine to NixOS after many years on Arch (I joined the BBS about 15 years ago) even though there were no real issues with Arch for me just because the concept had convinced me so quickly.

I will say that the experience is not perfect, but that’s not an euphemism. I’m very happy with how everything works. The approach might have issues with certain applications (as you mentioned desktop environments; another big one is Steam) but I rather consider this shoddy application behavior than system shortcomings.