0.1.8 on NixOS crashing the system

[djmaze]

Running NixOS 24.05, I was using niri 0.1.6 from NixOS stable before. Today I tried running 0.1.8 from NixOS unstable – from the tty using exec niri --session, as I was doing before. niri outputs some logs and then there is just a black screen and the system seems to have been totally halted (not even able to switch to a different tty via keyboard). I need to turn the laptop off. The first time after turning it on again, the screen stays black. I need to turn it off a second time until it gets back to life. So it seems something really severe stuff happening there.

I experienced a few kernel panics before with niri, while something like this never happened with Hyprland.

This is on a Thinkpad X1 Yoga 2nd Gen. I did not yet have time to dig deeper yet – that's why I did not open an issue yet. But is anyone else seeing these kinds of crashes?

[YaLTeR]

Black screen usually means that niri failed to initialize the GPU. Though, the rest of the compositor should work, i.e. Mod+Shift+E => Enter should exit it, or, indeed, switching to a different TTY. So that's the weird part that you can't switch to a different TTY.

It can fail to initialize the GPU for example if on NixOS you get a Mesa version mismatch somehow.

Try getting the niri output when it black screens?

[djmaze]

I was just using nix run when trying niri-flake.

Tbh, I am still not very deep into NixOS yet. So not using flakes or overlays for my system yet. Guess I just want to use the niri-stable package for now. Probably need to find out about overlays first. Thanks!

[djmaze]

Okay, I managed to switch my system configuration to use a flake.nix as well. Now I could add niri.url = "github:sodiboo/niri-flake"; to the inputs and then add nixpkgs.overlays = [ inputs.niri.overlays.niri ]; to my configuration.nix, as well as niri-stable to environment.systemPackages. After rebuilding the system, still the old niri version is symlinked though.

I cannot use your home-manager modules since I do not have my homemanager config switched to flake modules (yet). Is there another way I can replace my system niri with your niri-stable one?

UPDATE: I found the newly built package in my nix store and was able to successfully start it. Yeah! Still the question remains on how to properly install it.

[sodiboo]

Do you have pkgs.niri installed to your home-manager home.packages? In that case, this will override the system package in your PATH. Try removing niri from your home configuration, and see if the systemwide niri package is now the main one in your PATH.

Also note that this is not some kind of hack, it is genuinely better to install niri in your NixOS system configuration because your home manager configuration has no idea what version of mesa your system actually has, whereas the NixOS configuration does.

[djmaze]

Ah, no, I guess that was a misunderstanding. I have it in my environment.systemPackages in the system configuration.nix. And I don't have any niri-related config in my home.nix.

Well, nvm, I found the culprit. Trying to install different niri versions, I had used nix-env as well, so I had old versions in my profile as well. Reminds me again not to use nix-env for installing packages -_-

So, all seems to be working. Thanks for your work!

[sodiboo]

Ah, no, I guess that was a misunderstanding. I have it in my environment.systemPackages in the system configuration.nix. And I don't have any niri-related config in my home.nix.

I don't think i misunderstood. I understood that you had it globally, but since it was not being actually used it was also clearly installed in some user-specific way. I guessed home.packages would be the most likely culprit, but yeah nix-env would net you the same result. Anything installed as the user will take precedence over the system installation, declarative or not. Glad you figured it out! Have fun with niri :3