Debugging 'home.stateVersion is used but not defined.'

impermanence.nix

{
  lib,
  inputs,
  options,
  osOptions,
  hmOptions,
  config,
  osConfig,
  ...
}:
with lib;
let
  cfg = config.impermanence;
in
{
  inputs = {
    disko = {
      url = "github:nix-community/disko";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    impermanence.url = "github:tmarkov/impermanence"; # TODO: Change to nix-community when they fixed https://github.com/nix-community/impermanence/issues/154
  };

  osImports = [
    inputs.disko.nixosModules.default
    inputs.impermanence.nixosModules.impermanence
  ];
  hmImports = [ inputs.impermanence.nixosModules.home-manager.impermanence ];

  options.impermanence =
    let
      #os =
      #(modules.evalModules {
      #  modules =
      #    [ { _module.args.name = "/persist/system"; } ]
      #    #++ (options.os.type.getSubOptions [ ])
      #    ++ osOptions;#.environment.persistence.type.nestedTypes.elemType.getSubModules;
      #}).options;
      #	osConfig.environment.pdskfcasjdna;
      #hm = (options.hm.type.getSubOptions [ ]).home.persistence.type.getSubOptions [ ];
      os = osOptions.environment.persistence "/persist/system";
      #hm = hmOptions.home.persistence "/persist/home";
      #hm = builtins.trace (osOptions.home-manager.users.type.getSubModules) (
      #  (lib.evalModules {
      #    modules = [ { _module.args.name = "noah"; } ] ++ osOptions.home-manager.users.type.getSubModules;
      #  }).options.home.persistence.type.getSubOptions
      #    [ ]
      #);
      #hm = (options.os.type.getSubOptions []).home-manager.users.value;  #options.os.value.home-manager.users.noah.home.stateVersion;
      #hm = builtins.trace (builtins.attrNames options.os.value) 1;
      #newOsOptions = ((lib.evalModules { modules = options.os.type.getSubModules; })).options;
      #newOsOptions =
      #  (lib.evalModules { modules = options.os.type.getSubModules; }).options;
      #newOsOptions = (evalModules {modules=options.os.type.getSubModules;}).options;
      newOsOptions = options.os.type.getSubOptions [];
      hm =
        (evalModules {
          modules = newOsOptions.home-manager.users.type.getSubModules ++ [
          ];
        }).options.home.persistence.type.getSubOptions [];
    in
    #osOptions.home-manager.users.type.getSubOptions [ ];
    #builtins.trace (builtins.attrNames newOsOptions.options.home-manager.users.value.noah.home.stateVersion)
    #  osOptions.home-manager.users.type.getSubOptions []).home.persistence.type.getSubOptions [];
    #builtins.trace (builtins.attrNames ((options.os.type.getSubOptions [ ]).home-manager.users.value)) {
    # builtins.trace (builtins.attrNames (options.os.value.home-manager.users))
    {
      enable = mkEnableOption "impermanence";
      disk = mkOption {
        type = with types; uniq str;
        example = "sda";
        description = "The disk for disko to manager and to use for impermanence.";
      };
      os = {
        inherit (os) files directories;
      };
      hm = {
        inherit (hm) files directories;
      };
    };

  config = mkIf cfg.enable {
    # TODO assertions = [ { assertion = cfg.disk != null; } ]; # The disk option may not be set otherwise, this assertion never actually fails, but forces nix to evaluate cfg.disk

    os = {
      disko.devices = {
        disk.main = {
          device = "/dev/${cfg.disk}";
          type = "disk";
          content = {
            type = "gpt";
            partitions = {
              boot = {
                name = "boot";
                size = "1M";
                type = "EF02";
              };
              esp = {
                name = "ESP";
                size = "500M";
                type = "EF00";
                content = {
                  type = "filesystem";
                  format = "vfat";
                  mountOptions = [ "umask=0077" ];
                  mountpoint = "/boot";
                };
              };
              swap = {
                size = "4G";
                content = {
                  type = "swap";
                  resumeDevice = true;
                };
              };
              root = {
                name = "root";
                size = "100%";
                content = {
                  type = "lvm_pv";
                  vg = "root_vg";
                };
              };
            };
          };
        };
        lvm_vg.root_vg = {
          type = "lvm_vg";
          lvs.root = {
            size = "100%FREE";
            content = {
              type = "btrfs";
              extraArgs = [ "-f" ];
              subvolumes = {
                "/root".mountpoint = "/";
                "/persist" = {
                  mountOptions = [
                    "subvol=persist"
                    "noatime"
                  ];
                  mountpoint = "/persist";
                };
                "/nix" = {
                  mountOptions = [
                    "subvol=nix"
                    "noatime"
                  ];
                  mountpoint = "/nix";
                };
              };
            };
          };
        };
      };

      boot.initrd.postDeviceCommands = lib.mkAfter ''
        mkdir /btrfs_tmp
        mount /dev/root_vg/root /btrfs_tmp
        if [[ -e /btrfs_tmp/root ]]; then
          mkdir -p /btrfs_tmp/old_roots
          timestamp=$(date --date="@$(stat -c %Y /btrfs_tmp/root)" "+%Y-%m-%-d_%H:%M:%S")
          mv /btrfs_tmp/root "/btrfs_tmp/old_roots/$timestamp"
        fi

        delete_subvolume_recursively() {
          IFS=$'\n'
          for i in $(btrfs subvolume list -o "$1" | cut -f 9- -d ' '); do
            delete_subvolume_recursively "/btrfs_tmp/$i"
          done
          btrfs subvolume delete "$1"
        }

        for i in $(find /btrfs_tmp/old_roots/ -mindepth 1 -maxdepth 1 -mtime +30); do
          delete_subvolume_recursively "$i"
        done

        btrfs subvolume create /btrfs_tmp/root
        umount /btrfs_tmp
      '';

      fileSystems."/persist".neededForBoot = true;
      environment.persistence."/persist/system" = {
        hideMounts = true;
        directories = [
          "/var/log"
          "/var/lib/nixos"
          "/var/lib/systemd/coredump"
          "/etc/nixos"
        ] ++ cfg.os.directories;
        files = [
          "/etc/machine-id"
          {
            file = "/var/keys/secret_file";
            parentDirectory.mode = "u=rwx,g=,o=";
          }
        ] ++ cfg.os.files;
      };

      systemd.tmpfiles.rules = [ "d /persist/home 0700 noah users -" ];
      programs.fuse.userAllowOther = true;
    };

    hm.home.persistence."/persist/home" = {
      allowOther = true;
      directories = [
        "Downloads"
        "Music"
        "Pictures"
        "Documents"
        "Videos"
        ".gnupg"
        ".local/share/keyrings" # TODO: Remove if unused
        ".local/share/direnv" # TODO: Remove if unused
      ] ++ cfg.hm.directories;
      files = [ ".screenrc" ] ++ cfg.hm.files; # TODO: Remove if unused
    };
  };
}