I hopped from arch (2010-2019) to Nixos (2019-2023). I had my issues with it but being a functional programmer, I really liked the declarative style of configuring your OS. That was until last week. I decided to try out void Linux (musl). I’m happy with it so far.
Why did I switch?
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Nix is extremely slow and data intensive (compared to xbps). I mean sometimes 100-1000x or more. I know it is not a fair comparison because nix is doing much more. Even for small tweaks or dependency / toolchain update it’ll download/rebuild all packages. This would mean 3-10GB (or more) download on Nixos for something that is a few KB or MB on xbps.
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Everything is noticeably slower. My system used way more CPU and Ram even during idle. CPU was at 1-3% during idle and my battery life was 2 to 3.5h. Xfce idle ram usage was 1.5 GB on Nixos. On Void it’s around 0.5GB. I easily get 5-7h of battery life for my normal usage. It is 10h-12h if I am reading an ebook.
Nix disables a lot of compiler optimisations apparently for reproducibility. Maybe this is the reason?
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Just a lot of random bugs. Firefox would sometimes leak memory and hang. I have only 8 GB of ram. WiFi reconnecting all the time randomly. No such issues so far with void.
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Of course the abstractions and the language have a learning curve. It’s harder for a beginner to package or do something which is not already exposed as an option. (This wasn’t a big issue for me most of the time.)
For now, I’ll enjoy the speed and simplicity of void. It has less packages compared to nix but I have flatpak if needed. So far, I had to install only Android studio with it.
My verdict is to use Nixos for servers and shared dev environments. For desktop it’s probably not suitable for most.
In my experience, doing small changes to your nix config when using nix flakes seems to be faster. For me it only rebuilds everything when I run nix flake update before running sudo nixos-rebuild switch so it seems faster because it only does the thing that I changed instead of updating everything.
Also this in your configure.nix:
nix.registry = { nixpkgs = { from = { type = "indirect"; id = "nixpkgs"; }; to = { type = "path"; path = inputs.nixpkgs.outPath; }; }; };
This will create an entry in the nix registry pointing to your currently installed version and stop
nix search
from constantly updating the package list.Are there any tradeoffs I need to accept to use this?
No, it just makes the
nix
command use the samenixpkgs
repository your system is already using. Without itnix
will constantly redownload the latestnixpkgs-unstable
which is very slow. You will get slightly older software when you do something likenix run nixpkgs#blender
(“old” here meaning the same version as if you had it installed on your current system), but if you just want to try something out, you probably care more about it being fast than the latest version.And if you care about lastest stuff you’ll can just make yourself a
nixpkgs-unstable
registry entry with:and than do:
Updating your OS isn’t impacted by any of this at all, as that happens via the
/etc/nixos/flake.lock
file as before.PS: This assumes you are using flakes and the new
nix
command, both of which are still marked as experiment and not enabled the default.Thanks a lot. I will give it a try. By the way, are you also using the NUR? Do you maybe know if I can configure the
nix.registry
to allow using NUR packages usingnix shell
as well?Yeah. Most small changes will not rebuild everything. It’s just the core dependency updates that are most expensive. Like say openssl got a minor update. Now every package that depends on it needs to be rebuilt and rehashed because of the way nix store works.
Does Nix have Guix-style grafts? I know that in theory that is how Guix lessens the minor-update-to-core dependency problem. But I only use Guix for dev environments so I don’t know how well it works in practice.
Nix doesn’t support that officially, there is
replace-dependency
, but it’s not in common use:https://nixos.wiki/wiki/Documentation_Gaps#Does_nix_support_binary_grafting_like_guix.3F
There is also
patchelf
to adjust the RPATH and other stuff backed into compiled binaries, which is in common use, but not for patching.yeah that’s currently in the works (ca-derivations)