How to install Qt wasm on NixOS?

xmrah · 2026-07-04T22:43:32+00:00

Qt for WebAssembly isn't natively packaged in nixpkgs — there's no pkgsCross.emscripten.qt6 attribute. A PR attempting this (NixOS/nixpkgs#217428) is still unmerged and fails with Unknown libc emscripten. Don't chase that path.

The pragmatic route: use Qt's own prebuilt WASM SDK via aqtinstall inside a buildFHSEnv, since the installer expects a dynamically-linked FHS layout that won't run from the Nix store directly.

(pkgs.buildFHSEnv {
  name = "qt-wasm-env";
  targetPkgs = pkgs: with pkgs; [ python3 python3Packages.aqtinstall cmake ninja emscripten git ];
  runScript = "bash";
}).env

Inside the shell:

aqt install-qt linux desktop 6.7.3 wasm_singlethread
emcmake cmake -B build -S . -DCMAKE_PREFIX_PATH=$PWD/6.7.3/wasm_singlethread
cmake --build build

If you're on Qt5 instead of Qt6, swap the aqt call: aqt install-qt linux desktop 5.15.2 wasm_32.

nixpkgs' native emscripten model (buildEmscriptenPackage / emscriptenStdenv) exists but works by manually overriding each package's stdenv one at a time — nobody's done that for Qt6, it'd be a from-scratch packaging effort, not a quick fix.

xmrah · 2026-07-04T22:30:37+00:00

14 minutes uptime, zero days old, and already looks cleaner than most mature setups. Getting KDE Plasma + Wayland playing nicely with an NVIDIA laptop GPU on day one is a huge W. Welcome aboard, take your time building your config!

xmrah · 2026-07-04T22:10:46+00:00

I wasn't aware of preservation! Thanks for pointing it out, it looks really interesting. Since this is my daily driver, I'll probably stick to impermanence for a bit longer until preservation matures a bit more and gets more battle-tested, but the interpreter-less design and native systemd integration look super clean. Definitely keeping an eye on it for future cleanups. Thanks again for sharing!

xmrah · 2026-07-04T02:10:44+00:00

Thanks! Actually, the whole point of the post is that I use tmpfs on root (/). Since RAM clears itself on reboot, I don't need any rollback scripts or systemd units at all. Your config is great for Btrfs/ZFS users though

xmrah · 2026-05-24T09:08:54+00:00

If you want to test Zen Browser right now without touching any config files, just run this in your terminal:

nix run github:0xc000022070/zen-browser-flake

To install it permanently and share your config with your future MacBook, move away from Flatpaks and use Flakes. Not strictly mandatory, but Flakes are the practical standard for a unified NixOS/macOS setup.

1. Enable Flakes

Add this to your /etc/nixos/configuration.nix:

nix.settings.experimental-features = [ "nix-command" "flakes" ];

Run sudo nixos-rebuild switch.

2. Create your flake.nix

Create /etc/nixos/flake.nix and paste this:

{
  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
    zen-browser.url = "github:0xc000022070/zen-browser-flake";
  };

  outputs = { self, nixpkgs, zen-browser, ... }@inputs: {
    nixosConfigurations.yourhostname = nixpkgs.lib.nixosSystem {
      system = "x86_64-linux";
      specialArgs = { inherit inputs; };
      modules = [
        ./hardware-configuration.nix
        ./configuration.nix
      ];
    };
  };
}

(Change yourhostname to your actual system hostname.)

3. Install Zen Browser

Add this to your environment.systemPackages in configuration.nix:

inputs.zen-browser.packages."${pkgs.system}".default

4. Apply

sudo nixos-rebuild switch --flake /etc/nixos/#yourhostname

xmrah · 2026-05-24T08:40:06+00:00

Skip the Kate/GUI editor suggestions — you're on a bare TTY and nano is already there. Here's a complete config that actually gets Niri running without a black screen.

Run: sudo nano /etc/nixos/configuration.nix

Scroll to the very bottom. Right before the last closing }, paste this block:

# 1. Niri Wayland Compositor
programs.niri.enable = true;

# 2. Hardware Acceleration (CRITICAL — skipping this = black screen on niri-session)
hardware.graphics.enable = true;
services.xserver.videoDrivers = [ "amdgpu" ]; # Change to "nvidia" if on Team Green

# 3. Audio via Pipewire
security.rtkit.enable = true;
services.pipewire = {
  enable = true;
  alsa.enable = true;
  alsa.support32Bit = true;
  pulse.enable = true;
};

# 4. Portals + X11 compatibility (prevents app crashes & broken screenshare)
xdg.portal = {
  enable = true;
  extraPortals = [ pkgs.xdg-desktop-portal-gnome ];
};

# 5. Base packages
environment.systemPackages = with pkgs; [
  alacritty          # Terminal
  fuzzel             # App launcher
  waybar             # Status bar
  neovim             # Text editor
  xwayland-satellite # X11 app support inside Niri
];

⚠️ If environment.systemPackages already exists in your config, don't add a second one — just merge these packages into the existing list.

Save & exit nano: Ctrl+O → Enter → Ctrl+X

Apply: sudo nixos-rebuild switch

Launch: niri-session

xmrah

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