'anonymous lambda' called without required argument 'toRustTarget'

[siddharth-narayan]

On NixOS unstable, fully updated

With
lanzaboote.url = "github:nix-community/lanzaboote";
as part of inputs in flake.nix

$ sudo nixos-rebuild switch
warning: Git tree '/etc/nixos' is dirty
warning: updating lock file '"/etc/nixos/flake.lock"':
• Updated input 'lanzaboote/nixpkgs':
    follows 'nixpkgs'
  → 'github:NixOS/nixpkgs/2fad6eac6077f03fe109c4d4eb171cf96791faa4?narHash=sha256-sKoIWfnijJ0%2B9e4wRvIgm/HgE27bzwQxcEmo2J/gNpI%3D' (2025-11-27)
warning: Git tree '/etc/nixos' is dirty
building the system configuration...
warning: Git tree '/etc/nixos' is dirty
error:
       … while calling the 'head' builtin
         at /nix/store/fqyqwsw82v7jr6ncgrrg7cama5sl577r-source/lib/attrsets.nix:1696:13:
         1695|           if length values == 1 || pred here (elemAt values 1) (head values) then
         1696|             head values
             |             ^
         1697|           else

       … while evaluating the attribute 'value'
         at /nix/store/fqyqwsw82v7jr6ncgrrg7cama5sl577r-source/lib/modules.nix:1118:7:
         1117|     // {
         1118|       value = addErrorContext "while evaluating the option `${showOption loc}':" value;
             |       ^
         1119|       inherit (res.defsFinal') highestPrio;

       … while evaluating the option `system.build.toplevel':

       … while evaluating definitions from `/nix/store/fqyqwsw82v7jr6ncgrrg7cama5sl577r-source/nixos/modules/system/activation/top-level.nix':

       … while evaluating the option `system.systemBuilderArgs':

       … while evaluating definitions from `/nix/store/fqyqwsw82v7jr6ncgrrg7cama5sl577r-source/nixos/modules/system/activation/top-level.nix':

       … while evaluating the option `system.build.installBootLoader':

       … while evaluating definitions from `/nix/store/fqyqwsw82v7jr6ncgrrg7cama5sl577r-source/nixos/modules/system/boot/loader/external/external.nix':

       … while evaluating the option `boot.loader.external.installHook':

       … while evaluating the option `boot.lanzaboote.installCommand':

       (stack trace truncated; use '--show-trace' to show the full, detailed trace)

       error: function 'anonymous lambda' called without required argument 'toRustTarget'
       at /nix/store/0ari002ay63h19h823qbhvl0b4x99zsd-source/lib/rust-bin.nix:3:1:
            2| # Provide the content of `rust-bin`.
            3| {
             | ^
            4|   lib,
Command 'nix --extra-experimental-features 'nix-command flakes' build --print-out-paths '/etc/nixos#nixosConfigurations."saturn".config.system.build.toplevel' --no-link' returned non-zero exit status 1

And this other error while pinning to v0.4.3 in flake inputs

warning: Git tree '/etc/nixos' is dirty
building the system configuration...
warning: Git tree '/etc/nixos' is dirty
error:
       … while calling the 'head' builtin
         at /nix/store/fqyqwsw82v7jr6ncgrrg7cama5sl577r-source/lib/attrsets.nix:1696:13:
         1695|           if length values == 1 || pred here (elemAt values 1) (head values) then
         1696|             head values
             |             ^
         1697|           else

       … while evaluating the attribute 'value'
         at /nix/store/fqyqwsw82v7jr6ncgrrg7cama5sl577r-source/lib/modules.nix:1118:7:
         1117|     // {
         1118|       value = addErrorContext "while evaluating the option `${showOption loc}':" value;
             |       ^
         1119|       inherit (res.defsFinal') highestPrio;

       … while evaluating the option `system.build.toplevel':

       … while evaluating definitions from `/nix/store/fqyqwsw82v7jr6ncgrrg7cama5sl577r-source/nixos/modules/system/activation/top-level.nix':

       … while evaluating the option `system.systemBuilderArgs':

       … while evaluating definitions from `/nix/store/fqyqwsw82v7jr6ncgrrg7cama5sl577r-source/nixos/modules/system/activation/top-level.nix':

       … while evaluating the option `system.build.installBootLoader':

       … while evaluating definitions from `/nix/store/fqyqwsw82v7jr6ncgrrg7cama5sl577r-source/nixos/modules/system/boot/loader/external/external.nix':

       … while evaluating the option `boot.loader.external.installHook':

       (stack trace truncated; use '--show-trace' to show the full, detailed trace)

       error: Stable 1.86.0 is not available
Command 'nix --extra-experimental-features 'nix-command flakes' build --print-out-paths '/etc/nixos#nixosConfigurations."saturn".config.system.build.toplevel' --no-link' returned non-zero exit status 1.

Making lanzaboote follow nixpkgs in flakes does not change the outcome if that helps

[DaRacci]

I can concur on the error reporting error: Stable 1.86.0 is not available, looks like upstream dropped support for that rust version and we need a new patch + release.

[DaRacci]

Seems that the flake input may not have been updated during the release manually adding a updated input for rust-overlay allows the release to build.

[siddharth-narayan]

Yes, thanks for the tip! I had to fully delete flake.lock, although I don't know why nix flake update didn't update everything automatically

[tillnelown]

Had the same error when updating 25.05 to 25.11, deleting and recreating flake.lock fixed it.

[blitz]

Are you overriding Lanzaboote inputs? If so, can you try without?

[siddharth-narayan]

I just set the inputs to the same nixpkgs I used. I've fixed it now by deleting flake.lock like I mentioned above, but I can send the old one if it would help.