`self` is an undocumented required deprecated argument for `lib/default.nix`

[yajo]

Describe the bug

Following this example from docs, nix check fails.

To Reproduce

Steps to reproduce the behavior:

1. Unzip test.zip.
2. Enter the folder.
3. Run nix flake check

warning: unknown flake output '__functor'
error:
       … while checking flake output 'lib'
         at /nix/store/8s6nkmgdi0q0ycrm2c761b0bcp10x1x7-source/lib/default.nix:540:7:
          539|
          540|       lib = tryImport (src + "/lib") specialArgs;
             |       ^
          541|

       … from call site
         at /nix/store/8s6nkmgdi0q0ycrm2c761b0bcp10x1x7-source/lib/default.nix:77:57:
           76|   # Imports the path and pass the `args` to it if it exists, otherwise, return an empty attrset.
           77|   tryImport = path: args: optionalPathAttrs path (path: import path args);
             |                                                         ^
           78|

       error: function 'anonymous lambda' called with unexpected argument 'self'
       at /nix/store/lrlxfks43vviqf0mn51pjmb6rqbqs51b-source/lib/default.nix:1:1:
            1| {
             | ^
            2|   flake,

Expected behavior
OK

System information

• system: "x86_64-linux"
• host os: Linux 6.12.10-zen1, NixOS, 24.11 (Vicuna), 24.11.20250316.a1185f4
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.24.12
• nixpkgs: /nix/store/2d1ahim48jhzg4bbm97mvjlb4p7fpan3-source

Additional context