https://github.com/Hayao0819/dotfiles/blob/57014e53b7bfb97eac09b32e5cf279587f7d489e/flake.nix#L83

nix.log

❯ export NIXPKGS_ALLOW_BROKEN=1 && nix build .#nixosConfigurations.Installer.config.system.build.isoImage --show-trace
error:
       … while calling the 'derivationStrict' builtin
         at <nix/derivation-internal.nix>:34:12:
           33|
           34|   strict = derivationStrict drvAttrs;
             |            ^
           35|

       … while evaluating derivation 'nixos-24.11.20241205.4dc2fc4-x86_64-linux.iso'
         whose name attribute is located at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/stdenv/generic/make-derivation.nix:336:7

       … while evaluating attribute 'sources' of derivation 'nixos-24.11.20241205.4dc2fc4-x86_64-linux.iso'
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/nixos/lib/make-iso9660-image.nix:76:3:
           75|
           76|   sources = map (x: x.source) contents;
             |   ^
           77|   targets = map (x: x.target) contents;

       … while evaluating list element at index 1

       … while calling anonymous lambda
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/nixos/lib/make-iso9660-image.nix:76:18:
           75|
           76|   sources = map (x: x.source) contents;
             |                  ^
           77|   targets = map (x: x.target) contents;

       … while evaluating the attribute 'source'
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/nixos/modules/installer/cd-dvd/iso-image.nix:815:11:
          814|         }
          815|         { source = config.system.build.initialRamdisk + "/" + config.system.boot.loader.initrdFile;
             |           ^
          816|           target = "/boot/" + config.system.boot.loader.initrdFile;

       … while calling the 'getAttr' builtin
         at <nix/derivation-internal.nix>:44:19:
           43|       value = commonAttrs // {
           44|         outPath = builtins.getAttr outputName strict;
             |                   ^
           45|         drvPath = strict.drvPath;

       … while calling the 'derivationStrict' builtin
         at <nix/derivation-internal.nix>:34:12:
           33|
           34|   strict = derivationStrict drvAttrs;
             |            ^
           35|

       … while evaluating derivation 'initrd-linux-6.12.1'
         whose name attribute is located at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/stdenv/generic/make-derivation.nix:336:7

       … while evaluating attribute 'exportReferencesGraph' of derivation 'initrd-linux-6.12.1'
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/build-support/kernel/make-initrd.nix:105:3:
          104|   # See #36268.
          105|   exportReferencesGraph =
             |   ^
          106|     lib.zipListsWith

       … while evaluating one element of the list

       … while evaluating the attribute 'object'
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/nixos/modules/system/boot/stage-1.nix:349:11:
          348|         }
          349|         { object = "${modulesClosure}/lib";
             |           ^
          350|           symlink = "/lib";

       … while calling the 'getAttr' builtin
         at <nix/derivation-internal.nix>:44:19:
           43|       value = commonAttrs // {
           44|         outPath = builtins.getAttr outputName strict;
             |                   ^
           45|         drvPath = strict.drvPath;

       … while calling the 'derivationStrict' builtin
         at <nix/derivation-internal.nix>:34:12:
           33|
           34|   strict = derivationStrict drvAttrs;
             |            ^
           35|

       … while evaluating derivation 'linux-6.12.1-modules-shrunk'
         whose name attribute is located at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/stdenv/generic/make-derivation.nix:336:7

       … while evaluating attribute 'kernel' of derivation 'linux-6.12.1-modules-shrunk'
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/build-support/kernel/modules-closure.nix:13:11:
           12|   nativeBuildInputs = [ nukeReferences kmod ];
           13|   inherit kernel firmware rootModules allowMissing;
             |           ^
           14|   allowedReferences = ["out"];

       … while calling the 'getAttr' builtin
         at <nix/derivation-internal.nix>:44:19:
           43|       value = commonAttrs // {
           44|         outPath = builtins.getAttr outputName strict;
             |                   ^
           45|         drvPath = strict.drvPath;

       … while calling the 'derivationStrict' builtin
         at <nix/derivation-internal.nix>:34:12:
           33|
           34|   strict = derivationStrict drvAttrs;
             |            ^
           35|

       … while evaluating derivation 'linux-6.12.1-modules'
         whose name attribute is located at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/stdenv/generic/make-derivation.nix:336:7

       … while evaluating attribute 'passAsFile' of derivation 'linux-6.12.1-modules'
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/build-support/trivial-builders/default.nix:60:9:
           59|         inherit buildCommand name;
           60|         passAsFile = [ "buildCommand" ]
             |         ^
           61|           ++ (derivationArgs.passAsFile or [ ]);

       … while evaluating the attribute 'passAsFile'
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/build-support/buildenv/default.nix:87:5:
           86|     # XXX: The size is somewhat arbitrary
           87|     passAsFile = if builtins.stringLength pkgs >= 128*1024 then [ "pkgs" ] else [ ];
             |     ^
           88|   }

       … while evaluating a branch condition
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/build-support/buildenv/default.nix:87:18:
           86|     # XXX: The size is somewhat arbitrary
           87|     passAsFile = if builtins.stringLength pkgs >= 128*1024 then [ "pkgs" ] else [ ];
             |                  ^
           88|   }

       … in the argument of the not operator
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/build-support/buildenv/default.nix:87:48:
           86|     # XXX: The size is somewhat arbitrary
           87|     passAsFile = if builtins.stringLength pkgs >= 128*1024 then [ "pkgs" ] else [ ];
             |                                                ^
           88|   }

       … while calling the 'lessThan' builtin
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/build-support/buildenv/default.nix:87:48:
           86|     # XXX: The size is somewhat arbitrary
           87|     passAsFile = if builtins.stringLength pkgs >= 128*1024 then [ "pkgs" ] else [ ];
             |                                                ^
           88|   }

       … while calling the 'stringLength' builtin
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/build-support/buildenv/default.nix:87:21:
           86|     # XXX: The size is somewhat arbitrary
           87|     passAsFile = if builtins.stringLength pkgs >= 128*1024 then [ "pkgs" ] else [ ];
             |                     ^
           88|   }

       … while calling the 'toJSON' builtin
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/build-support/buildenv/default.nix:82:12:
           81|             nativeBuildInputs buildInputs;
           82|     pkgs = builtins.toJSON chosenOutputs;
             |            ^
           83|     extraPathsFrom = lib.optional includeClosures (writeClosure pathsForClosure);

       … while evaluating list element at index 1

       … while evaluating attribute 'paths'
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/build-support/buildenv/default.nix:57:5:
           56|   chosenOutputs = map (drv: {
           57|     paths =
             |     ^
           58|       # First add the usual output(s): respect if user has chosen explicitly,

       … while evaluating a branch condition
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/build-support/buildenv/default.nix:62:8:
           61|       # aren't expected to have multiple outputs.
           62|       (if (! drv ? outputSpecified || ! drv.outputSpecified)
             |        ^
           63|           && drv.meta.outputsToInstall or null != null

       … in the left operand of the AND (&&) operator
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/build-support/buildenv/default.nix:63:11:
           62|       (if (! drv ? outputSpecified || ! drv.outputSpecified)
           63|           && drv.meta.outputsToInstall or null != null
             |           ^
           64|         then map (outName: drv.${outName}) drv.meta.outputsToInstall

       … in the left operand of the OR (||) operator
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/build-support/buildenv/default.nix:62:36:
           61|       # aren't expected to have multiple outputs.
           62|       (if (! drv ? outputSpecified || ! drv.outputSpecified)
             |                                    ^
           63|           && drv.meta.outputsToInstall or null != null

       … in the argument of the not operator
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/build-support/buildenv/default.nix:62:14:
           61|       # aren't expected to have multiple outputs.
           62|       (if (! drv ? outputSpecified || ! drv.outputSpecified)
             |              ^
           63|           && drv.meta.outputsToInstall or null != null

       … from call site
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/build-support/buildenv/default.nix:62:14:
           61|       # aren't expected to have multiple outputs.
           62|       (if (! drv ? outputSpecified || ! drv.outputSpecified)
             |              ^
           63|           && drv.meta.outputsToInstall or null != null

       … while calling anonymous lambda
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/lib/types.nix:546:14:
          545|       merge = loc: defs:
          546|         map (x: x.value) (filter (x: x ? value) (concatLists (imap1 (n: def:
             |              ^
          547|           imap1 (m: def':

       … while evaluating the attribute 'value'
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/lib/modules.nix:864:27:
          863|     optionalValue =
          864|       if isDefined then { value = mergedValue; }
             |                           ^
          865|       else {};

       … while evaluating a branch condition
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/lib/modules.nix:853:9:
          852|       if isDefined then
          853|         if all (def: type.check def.value) defsFinal then type.merge loc defsFinal
             |         ^
          854|         else let allInvalid = filter (def: ! type.check def.value) defsFinal;

       … while calling the 'all' builtin
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/lib/modules.nix:853:12:
          852|       if isDefined then
          853|         if all (def: type.check def.value) defsFinal then type.merge loc defsFinal
             |            ^
          854|         else let allInvalid = filter (def: ! type.check def.value) defsFinal;

       … while calling anonymous lambda
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/lib/modules.nix:853:17:
          852|       if isDefined then
          853|         if all (def: type.check def.value) defsFinal then type.merge loc defsFinal
             |                 ^
          854|         else let allInvalid = filter (def: ! type.check def.value) defsFinal;

       … from call site
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/lib/modules.nix:853:22:
          852|       if isDefined then
          853|         if all (def: type.check def.value) defsFinal then type.merge loc defsFinal
             |                      ^
          854|         else let allInvalid = filter (def: ! type.check def.value) defsFinal;

       … while calling 'check'
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/lib/types.nix:528:15:
          527|       descriptionClass = "noun";
          528|       check = x: isStringLike x && builtins.substring 0 1 (toString x) == "/";
             |               ^
          529|       merge = mergeEqualOption;

       … in the right operand of the AND (&&) operator
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/lib/types.nix:528:33:
          527|       descriptionClass = "noun";
          528|       check = x: isStringLike x && builtins.substring 0 1 (toString x) == "/";
             |                                 ^
          529|       merge = mergeEqualOption;

       … while calling the 'substring' builtin
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/lib/types.nix:528:36:
          527|       descriptionClass = "noun";
          528|       check = x: isStringLike x && builtins.substring 0 1 (toString x) == "/";
             |                                    ^
          529|       merge = mergeEqualOption;

       … while calling the 'toString' builtin
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/lib/types.nix:528:60:
          527|       descriptionClass = "noun";
          528|       check = x: isStringLike x && builtins.substring 0 1 (toString x) == "/";
             |                                                            ^
          529|       merge = mergeEqualOption;

       … in the condition of the assert statement
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/lib/customisation.nix:366:17:
          365|       drvPath = assert condition; drv.drvPath;
          366|       outPath = assert condition; drv.outPath;
             |                 ^
          367|     };

       … while evaluating the attribute 'handled'
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/stdenv/generic/check-meta.nix:507:7:
          506|       # or, alternatively, just output a warning message.
          507|       handled =
             |       ^
          508|         (

       … from call site
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/stdenv/generic/check-meta.nix:511:13:
          510|           else if valid == "no" then (
          511|             handleEvalIssue { inherit meta attrs; } { inherit (validity) reason errormsg; }
             |             ^
          512|           )

       … while calling 'handleEvalIssue'
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/stdenv/generic/check-meta.nix:269:38:
          268|
          269|   handleEvalIssue = { meta, attrs }: { reason , errormsg ? "" }:
             |                                      ^
          270|     let

       … while calling the 'throw' builtin
         at /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/stdenv/generic/check-meta.nix:281:8:
          280|         else throw;
          281|     in handler msg;
             |        ^
          282|

       error: Package ‘zfs-kernel-2.2.6-6.12.1’ in /nix/store/5wvrlpfrwlmg24ywkybvidyzcvki6bwx-source/pkgs/os-specific/linux/zfs/generic.nix:217 is marked as broken, refusing to evaluate.

       a) To temporarily allow broken packages, you can use an environment variable
          for a single invocation of the nix tools.

            $ export NIXPKGS_ALLOW_BROKEN=1

          Note: When using `nix shell`, `nix build`, `nix develop`, etc with a flake,
                then pass `--impure` in order to allow use of environment variables.

       b) For `nixos-rebuild` you can set
         { nixpkgs.config.allowBroken = true; }
       in configuration.nix to override this.

       c) For `nix-env`, `nix-build`, `nix-shell` or any other Nix command you can add
         { allowBroken = true; }
       to ~/.config/nixpkgs/config.nix.