nixos/stage-1: always include util-linux mount

[chetgurevitch]

Updates stage-1.nix to make enabling util-linux's mount possible for multiple reasons, like the existing ZFS mount helper use case and the new X-mount.subdir use case.

Resolves #414390

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Nixpkgs 25.11 Release Notes (or backporting 24.11 and 25.05 Nixpkgs Release notes)
• Fits CONTRIBUTING.md.

---

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[ElvishJerricco]

Can we just.... always use util-linux mount? It's arguably always good to delegate to the mount helper, and to support the X-mount.* options that only util-linux supports. The only concern is if that grows the size of the initrd by an intolerable amount but I strongly suspect it'll only be a few kilobytes so we should just do it.

And yea while we're at it we should just move the mount.zfs part into the ZFS module.

[chetgurevitch]

I had that thought too, both changes sound good to me but will double check the size to make sure.

[chetgurevitch]

Yeah it's only 12kB, made it unconditional. The ZFS module now includes mount.zfs either in extraUtilsCommands or systemd.extraBin. Also I noticed zdb doesn't get added with boot.initrd.systemd, is that an oversight?

[qubitnano]

This has been working for me on two bcachefs on root machines with subvolumes.

[chetgurevitch]

@ElvishJerricco I believe this is ready for merge, been working for me and a few others for awhile. Currently there are some unrelated issues from outdated bcachefs-tools in 25.05 but once 1.25.3 is promoted those will disappear.

That part got resolved.

[chetgurevitch]

The failures aren't from the PR, if you look at the logs for the devShellTools failure it runs out of space, and the issue also occurs on master.

Looking at the logs for aarch64-linux reveals the system used for nixpkgs-review-gha is built without kvm support, which is responsible for the 4 additional failures.



The PR has no relevance to Darwin, but there seems to be a configuration issue for nixpkgs-review-gha there too.

Should be ready for merge.

[magneticflux-]

This is failing with boot.supportedFilesystems = [ "zfs" ]; boot.initrd.systemd.enable = true;, not sure about others. You might have intended to specify "mount.zfs" = "${cfgZfs.package}/sbin/mount.zfs"; so the dot isn't interpreted as an object property(?).

error: A definition for option `boot.initrd.systemd.extraBin.mount' is not of type `absolute path'. Definition values:
       - In `/nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/nixos/modules/tasks/filesystems/zfs.nix':
           {
             zfs = "/nix/store/hxg3s5l92y9n9m48p872i62dn5ck33hx-zfs-user-2.4.0-rc3/sbin/mount.zfs";
           }

Loooooong error

error:
       … while evaluating an expression to select 'drvPath' on it
         at «internal»:1:552:
       … while evaluating strict
         at «internal»:1:552:
       … while calling the 'derivationStrict' builtin
         at «internal»:1:208:
       … while evaluating derivation 'nixos-system-x-25.11.20251026.a10dede'
         whose name attribute is located at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/pkgs/stdenv/generic/make-derivation.nix:544:13

       … while evaluating attribute 'buildCommand' of derivation 'nixos-system-x-25.11.20251026.a10dede'
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/nixos/modules/system/activation/top-level.nix:71:7:
           70|       passAsFile = [ "extraDependencies" ];
           71|       buildCommand = systemBuilder;
             |       ^
           72|

       … from call site
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/nixos/modules/system/activation/top-level.nix:48:21:
           47|
           48|     ${config.system.systemBuilderCommands}
             |                     ^
           49|

       … while calling anonymous lambda
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/attrsets.nix:1188:17:
         1187|         mapAttrs (
         1188|           name: value:
             |                 ^
         1189|           if isAttrs value && cond value then recurse (path ++ [ name ]) value else f (path ++ [ name ]) value

       … from call site
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/attrsets.nix:1189:85:
         1188|           name: value:
         1189|           if isAttrs value && cond value then recurse (path ++ [ name ]) value else f (path ++ [ name ]) value
             |                                                                                     ^
         1190|         );

       … while calling anonymous lambda
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:275:71:
          274|           # For definitions that have an associated option
          275|           declaredConfig = mapAttrsRecursiveCond (v: !isOption v) (_: v: v.value) options;
             |                                                                       ^
          276|

       … while evaluating the attribute 'value'
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1118:7:
         1117|     // {
         1118|       value = addErrorContext "while evaluating the option `${showOption loc}':" value;
             |       ^
         1119|       inherit (res.defsFinal') highestPrio;

       … while calling the 'addErrorContext' builtin
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1118:15:
         1117|     // {
         1118|       value = addErrorContext "while evaluating the option `${showOption loc}':" value;
             |               ^
         1119|       inherit (res.defsFinal') highestPrio;

       … while evaluating the option `system.systemBuilderCommands':

       … while evaluating the attribute 'mergedValue'
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1166:5:
         1165|     # Type-check the remaining definitions, and merge them. Or throw if no definitions.
         1166|     mergedValue =
             |     ^
         1167|       if isDefined then

       … while evaluating isDefined
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1167:10:
         1166|     mergedValue =
         1167|       if isDefined then
             |          ^
         1168|         if type.merge ? v2 then

       … while evaluating defsFinal
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1225:17:
         1224|
         1225|     isDefined = defsFinal != [ ];
             |                 ^
         1226|

       … while evaluating the attribute 'values'
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1160:9:
         1159|       {
         1160|         values = defsSorted;
             |         ^
         1161|         inherit (defsFiltered) highestPrio;

       … while calling the 'any' builtin
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1154:14:
         1153|           # Avoid sorting if we don't have to.
         1154|           if any (def: def.value._type or "" == "order") defsFiltered.values then
             |              ^
         1155|             sortProperties defsFiltered.values

       … while evaluating the attribute 'values'
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1331:7:
         1330|     {
         1331|       values = concatMap (def: if getPrio def == highestPrio then [ (strip def) ] else [ ]) defs;
             |       ^
         1332|       inherit highestPrio;

       … while calling the 'concatMap' builtin
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1331:16:
         1330|     {
         1331|       values = concatMap (def: if getPrio def == highestPrio then [ (strip def) ] else [ ]) defs;
             |                ^
         1332|       inherit highestPrio;

       … while calling the 'concatMap' builtin
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1134:26:
         1133|         # Process mkMerge and mkIf properties.
         1134|         defsNormalized = concatMap (
             |                          ^
         1135|           m:

       … while calling anonymous lambda
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1135:11:
         1134|         defsNormalized = concatMap (
         1135|           m:
             |           ^
         1136|           map (

       … while calling the 'map' builtin
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1136:11:
         1135|           m:
         1136|           map (
             |           ^
         1137|             value:

       … while calling the 'addErrorContext' builtin
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1145:14:
         1144|               }
         1145|           ) (addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))
             |              ^
         1146|         ) defs;

       … while evaluating definitions from `/nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/nixos/modules/system/boot/kernel.nix':

       … from call site
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1145:80:
         1144|               }
         1145|           ) (addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))
             |                                                                                ^
         1146|         ) defs;

       … while calling 'dischargeProperties'
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1282:5:
         1281|   dischargeProperties =
         1282|     def:
             |     ^
         1283|     if def._type or "" == "merge" then

       … from call site
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1287:31:
         1286|       if isBool def.condition then
         1287|         if def.condition then dischargeProperties def.content else [ ]
             |                               ^
         1288|       else

       … while calling 'dischargeProperties'
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1282:5:
         1281|   dischargeProperties =
         1282|     def:
             |     ^
         1283|     if def._type or "" == "merge" then

       … while evaluating an expression to select '_type' on it
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1283:8:
         1282|     def:
         1283|     if def._type or "" == "merge" then
             |        ^
         1284|       concatMap dischargeProperties def.contents

       … while evaluating def
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1283:8:
         1282|     def:
         1283|     if def._type or "" == "merge" then
             |        ^
         1284|       concatMap dischargeProperties def.contents

       … while evaluating the attribute 'content'
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1442:23:
         1441|     _type = "if";
         1442|     inherit condition content;
             |                       ^
         1443|   };

       … while evaluating initrdPath
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/nixos/modules/system/boot/kernel.nix:415:19:
          414|
          415|           ln -s ${initrdPath} $out/initrd
             |                   ^
          416|

       … while calling the 'getAttr' builtin
         at «internal»:1:500:
       … while calling the 'derivationStrict' builtin
         at «internal»:1:208:
       … while evaluating derivation 'initrd-linux-6.17.5'
         whose name attribute is located at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/pkgs/stdenv/generic/make-derivation.nix:544:13

       … while evaluating attribute 'contents' of derivation 'initrd-linux-6.17.5'
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/pkgs/build-support/kernel/make-initrd-ng.nix:94:5:
           93|     passAsFile = [ "contents" ];
           94|     contents = builtins.toJSON contents;
             |     ^
           95|

       … while calling the 'toJSON' builtin
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/pkgs/build-support/kernel/make-initrd-ng.nix:94:16:
           93|     passAsFile = [ "contents" ];
           94|     contents = builtins.toJSON contents;
             |                ^
           95|

       … while evaluating list element at index 34

       … while evaluating attribute 'source'

       … while calling anonymous lambda
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/attrsets.nix:1188:17:
         1187|         mapAttrs (
         1188|           name: value:
             |                 ^
         1189|           if isAttrs value && cond value then recurse (path ++ [ name ]) value else f (path ++ [ name ]) value

       … from call site
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/attrsets.nix:1189:85:
         1188|           name: value:
         1189|           if isAttrs value && cond value then recurse (path ++ [ name ]) value else f (path ++ [ name ]) value
             |                                                                                     ^
         1190|         );

       … while calling anonymous lambda
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:275:71:
          274|           # For definitions that have an associated option
          275|           declaredConfig = mapAttrsRecursiveCond (v: !isOption v) (_: v: v.value) options;
             |                                                                       ^
          276|

       … while evaluating the attribute 'value'
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1118:7:
         1117|     // {
         1118|       value = addErrorContext "while evaluating the option `${showOption loc}':" value;
             |       ^
         1119|       inherit (res.defsFinal') highestPrio;

       … while calling the 'addErrorContext' builtin
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1118:15:
         1117|     // {
         1118|       value = addErrorContext "while evaluating the option `${showOption loc}':" value;
             |               ^
         1119|       inherit (res.defsFinal') highestPrio;

       … while evaluating the option `boot.initrd.systemd.storePaths."[definition 4-entry 29]".source':

       (11 duplicate frames omitted)

       … while evaluating definitions from `/nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/nixos/modules/system/boot/systemd/initrd.nix':

       … from call site
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1145:80:
         1144|               }
         1145|           ) (addErrorContext "while evaluating definitions from `${m.file}':" (dischargeProperties m.value))
             |                                                                                ^
         1146|         ) defs;

       … while calling 'dischargeProperties'
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1282:5:
         1281|   dischargeProperties =
         1282|     def:
             |     ^
         1283|     if def._type or "" == "merge" then

       … while evaluating an expression to select '_type' on it
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1283:8:
         1282|     def:
         1283|     if def._type or "" == "merge" then
             |        ^
         1284|       concatMap dischargeProperties def.contents

       … while evaluating def
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1283:8:
         1282|     def:
         1283|     if def._type or "" == "merge" then
             |        ^
         1284|       concatMap dischargeProperties def.contents

       … while evaluating the attribute 'value'
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:805:21:
          804|             inherit (module) file;
          805|             inherit value;
             |                     ^
          806|           }) module.config

       … from call site
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:805:21:
          804|             inherit (module) file;
          805|             inherit value;
             |                     ^
          806|           }) module.config

       … while calling anonymous lambda
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/attrsets.nix:1188:17:
         1187|         mapAttrs (
         1188|           name: value:
             |                 ^
         1189|           if isAttrs value && cond value then recurse (path ++ [ name ]) value else f (path ++ [ name ]) value

       … from call site
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/attrsets.nix:1189:85:
         1188|           name: value:
         1189|           if isAttrs value && cond value then recurse (path ++ [ name ]) value else f (path ++ [ name ]) value
             |                                                                                     ^
         1190|         );

       … while calling anonymous lambda
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:275:71:
          274|           # For definitions that have an associated option
          275|           declaredConfig = mapAttrsRecursiveCond (v: !isOption v) (_: v: v.value) options;
             |                                                                       ^
          276|

       … while evaluating the attribute 'value'
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1118:7:
         1117|     // {
         1118|       value = addErrorContext "while evaluating the option `${showOption loc}':" value;
             |       ^
         1119|       inherit (res.defsFinal') highestPrio;

       … while calling the 'addErrorContext' builtin
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1118:15:
         1117|     // {
         1118|       value = addErrorContext "while evaluating the option `${showOption loc}':" value;
             |               ^
         1119|       inherit (res.defsFinal') highestPrio;

       … while evaluating the option `boot.initrd.systemd.contents."/bin".source':

       (19 duplicate frames omitted)

       … while evaluating derivation 'initrd-bin-env'
         whose name attribute is located at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/pkgs/stdenv/generic/make-derivation.nix:544:13

       … while evaluating attribute 'postBuild' of derivation 'initrd-bin-env'
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/pkgs/build-support/buildenv/default.nix:104:11:
          103|           extraPrefix
          104|           postBuild
             |           ^
          105|           nativeBuildInputs

       … while calling the 'concatStringsSep' builtin
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/nixos/modules/system/boot/systemd/initrd.nix:118:9:
          117|       find $out/sbin -maxdepth 1 -type l -print0 | xargs --null cp --no-dereference --no-clobber -t $out/bin/
          118|       ${concatStringsSep "\n" (
             |         ^
          119|         mapAttrsToList (n: v: ''

       … while calling anonymous lambda
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/nixos/modules/system/boot/systemd/initrd.nix:119:28:
          118|       ${concatStringsSep "\n" (
          119|         mapAttrsToList (n: v: ''
             |                            ^
          120|           ln -sf '${v}' $out/bin/'${n}'

       … while evaluating v
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/nixos/modules/system/boot/systemd/initrd.nix:120:21:
          119|         mapAttrsToList (n: v: ''
          120|           ln -sf '${v}' $out/bin/'${n}'
             |                     ^
          121|           ln -sf '${v}' $out/sbin/'${n}'

       … from call site
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/nixos/modules/system/boot/systemd/initrd.nix:120:21:
          119|         mapAttrsToList (n: v: ''
          120|           ln -sf '${v}' $out/bin/'${n}'
             |                     ^
          121|           ln -sf '${v}' $out/sbin/'${n}'

       … while calling anonymous lambda
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/types.nix:831:22:
          830|                 value = mapAttrs (
          831|                   n: v:
             |                      ^
          832|                   if lazy then

       … while evaluating the attribute 'optionalValue.value'
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1227:41:
         1226|
         1227|     optionalValue = if isDefined then { value = mergedValue; } else { };
             |                                         ^
         1228|   };

       … caused by explicit throw
         at /nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/lib/modules.nix:1181:11:
         1180|           in
         1181|           throw "A definition for option `${showOption loc}' is not of type `${type.description}'. Definition values:${showDefs allInvalid}"
             |           ^
         1182|       else

       error: A definition for option `boot.initrd.systemd.extraBin.mount' is not of type `absolute path'. Definition values:
       - In `/nix/store/h259dzilgbvpfsnlcyims14jrcdnx8fk-source/nixos/modules/tasks/filesystems/zfs.nix':
           {
             zfs = "/nix/store/hxg3s5l92y9n9m48p872i62dn5ck33hx-zfs-user-2.4.0-rc3/sbin/mount.zfs";
           }

[thefossguy]

I noticed that this breaks my setup of ZFS on root. The patch is good and yet reverting it resolves the issue for me. I haven't been able to dive deep and figure out why this is the case. Does anyone have insights for why it might cause issues? The sysroot.mount systemd unit fails during stage-1.

My NixOS configuration is here and the hostname for machine with ZFS on root is chaturvyas (it is an aarch64 machine so you will not be able to test it on x86 without some extra qemu setup).

[thefossguy]

Nevermind, I overlooked that the async mount option was being passed as a default from a different config file and that causes systemd.mount to "panic" in parsing Options= since sync/async is managed via zfs properties. I removed it and everything works as intended.