Date: 2022-10-19 PDT
[12:12:41.093] weston 10.0.0
               https://wayland.freedesktop.org
               Bug reports to: https://gitlab.freedesktop.org/wayland/weston/issues/
               Build: 10.0.0
[12:12:41.094] Command line: /nix/store/6l920wjzw38gvb2vcp1y2ajhhpfw3fn1-weston-10.0.0/bin/weston
[12:12:41.094] OS: Linux, 5.19.14, #1-NixOS SMP PREEMPT_DYNAMIC Wed Oct 5 08:40:55 UTC 2022, x86_64
[12:12:41.094] Flight recorder: enabled
[12:12:41.094] Starting with no config file.
[12:12:41.094] Output repaint window is 7 ms maximum.
[12:12:41.094] Loading module '/nix/store/6l920wjzw38gvb2vcp1y2ajhhpfw3fn1-weston-10.0.0/lib/libweston-10/drm-backend.so'
[12:12:41.096] initializing drm backend
[12:12:41.096] Trying logind launcher...
[12:12:41.098] logind: session control granted
[12:12:41.098] no drm device found
[12:12:41.098] fatal: failed to create compositor backend
Internal warning: debug scope 'drm-backend' has not been destroyed.

In reply to @charles:computer.surgery
this is why it's not working

In reply to @a-kenji:matrix.org
Oh, but you will need to patch the file anyway since it hardcodes mold to /usr/bin

In reply to @a-kenji:matrix.org
There is an open pr, which works well.

{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs";
    flake-utils.url = "github:numtide/flake-utils";

    fenix = {
      url = "github:nix-community/fenix";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    naersk = {
      url = "github:nix-community/naersk";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    
    upstream = {
      url = "github:0x192/universal-android-debloater?ref=0.5.1";
      flake = false;
    };
  };

  outputs =
    { self
    , nixpkgs
    , flake-utils

    , fenix
    , naersk
    , upstream
    }: flake-utils.lib.eachDefaultSystem (system:
    let
      pkgs = nixpkgs.legacyPackages.${system};
      toolchain = fenix.packages.${system}.toolchainOf {
        channel = "nightly";
        date = "2022-10-19";
        sha256 = "wqcIBI0cuNAj3g4Fpk83jajPpwlyV4EetYex1vInAFY=";
      };
    in
    {
      packages.default = (pkgs.callPackage naersk {
        inherit (toolchain) rustc cargo;
      }).buildPackage {
        src = "${upstream}";
        preConfigure = ''
          rm -r .cargo
        '';
      };

      checks = {
        packagesDefault = self.packages.${system}.default;
      };
    });
}

aktaboot this seems to be working