Nightly bcachefs nix user repository

your configuration.nix should look something like this:

{ config, pkgs, lib, ...}:
let
  yo-nur     = import (builtins.fetchTarball "https://github.com/YellowOnion/nur-bcachefs/archive/master.tar.gz") {};
in
{
  boot.kernelPackages = lib.mkOverride 0 (pkgs.linuxPackagesFor pkgs.bcachefs-kernel-kent);
  nixpkgs.overlays = [(super: final: { bcachefs-tools = yo-nur.bcachefs-tools;})];
  
  nix = {
    settings = {
      substituters = [
          "https://yo-nur.cachix.org"
          "https://cache.garnix.io"
      ];
      trusted-public-keys = [
        "yo-nur.cachix.org-1:E/RHfQMAZ90mPhvsaqo/GrQ3M1xzXf5Ztt0o+1X3+Bs="
        "cache.garnix.io:CTFPyKSLcx5RMJKfLo5EEPUObbA78b0YQ2DTCJXqr9g="
      ];
    };
  };
}

build iso:

    git clone https://github.com/YellowOnion/nur-bcachefs.git
    cd nur-bcachefs
    nix-build -A bcachefs-iso --option extra-substituters "https://yo-nur.cachix.org" --option extra-trusted-public-keys "yo-nur.cachix.org-1:E/RHfQMAZ90mPhvsaqo/GrQ3M1xzXf5Ztt0o+1X3+Bs="
    ls ./result/iso