formats: deprecate accidental lib.types aliases

[MattSturgeon]

Introduced in #335232 (commit 1f6ce17), see discussion: #335232 (comment)

cc @philiptaron

Things done

Tested using the repl:

$ nix repl
Nix 2.28.3
Type :? for help.

nix-repl> pkgs = import ./. { }

nix-repl> pkgsNoAliases = import ./. { config.allowAliases = false; }

nix-repl> pkgs.formats.attrsOf
evaluation warning: `formats.attrsOf' is deprcated, use `lib.types.attrsOf' instead.
«lambda attrsOf @ /home/matt/nixpkgs/pr/lib/types.nix:752:17»

nix-repl> pkgsNoAliases.formats.attrsOf
error:
       … while evaluating the attribute 'formats.attrsOf'
         at /home/matt/nixpkgs/pr/pkgs/top-level/all-packages.nix:996:5:
          995|     })
          996|     formats
             |     ^
          997|     ;

       error: attribute 'attrsOf' missing
       at «string»:1:1:
            1| pkgsNoAliases.formats.attrsOf
             | ^

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
  • sandbox = relaxed
  • sandbox = true
• 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
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• Nixpkgs 25.11 Release Notes (or backporting 24.11 and 25.05 Nixpkgs Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
• NixOS 25.11 Release Notes (or backporting 24.11 and 25.05 NixOS Release notes)
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md, pkgs/README.md, maintainers/README.md and other contributing documentation in corresponding paths.

---

Add a 👍 reaction to pull requests you find important.

[philiptaron]

I went looking to see how formats is used.

$ rg -wo 'formats\.\w+' --no-filename | sort | uniq -c | sort -rh
    129 formats.yaml
    124 formats.json
     97 formats.toml
     89 formats.ini
     20 formats.keyValue
     14 formats.iniWithGlobalSection
     11 formats.hocon
     11 formats.elixirConf
     10 formats.text
     10 formats.dataclass
      9 formats.javaProperties
      7 formats.php
      7 formats.libconfig
      6 formats.nix
      5 formats.c
      4 formats.asn1
      4 formats.add_parser
      3 formats.xml
      3 formats.pythonVars
      3 formats.lua
      3 formats.cdn
      2 formats.systemd
      2 formats.nrbf
      1 formats.yaml_1_1
      1 formats.tone_stream
      1 formats.sndfile
      1 formats.png
      1 formats.passthru
      1 formats.native_file
      1 formats.local_stream
      1 formats.gitIni

We should deprecate every item that was accidentally added.

[MattSturgeon]

We should deprecate every item that was accidentally added.

Looking at #166044, javaProperties is intentional.

Testing locally, it seems that all "unused" attrs are deprecated by this PR:

Details

$ nix repl
Nix 2.28.3
Type :? for help.
nix-repl> pkgs = import ./. {config.allowAliases = false;}

nix-repl> used = {
              yaml = null;
              json = null;
              toml = null;
              ini = null;
              keyValue = null;
              iniWithGlobalSection = null;
              hocon = null;
              elixirConf = null;
              text = null;
              dataclass = null;
              javaProperties = null;
              php = null;
              libconfig = null;
              nix = null;
              c = null;
              asn1 = null;
              add_parser = null;
              xml = null;
              pythonVars = null;
              lua = null;
              cdn = null;
              systemd = null;
              nrbf = null;
              yaml_1_1 = null;
              tone_stream = null;
              sndfile = null;
              png = null;
              passthru = null;
              native_file = null;
              local_stream = null;
              gitIni = null;
          }

nix-repl> fmt = pkgs.formats

nix-repl> builtins.intersectAttrs used fmt
{
  cdn = «lambda cdn @ /home/matt/nixpkgs/pr/pkgs/pkgs-lib/formats.nix:462:5»;
  elixirConf = «lambda elixirConf @ /home/matt/nixpkgs/pr/pkgs/pkgs-lib/formats.nix:534:5»;
  gitIni = «lambda gitIni @ /home/matt/nixpkgs/pr/pkgs/pkgs-lib/formats.nix:316:11»;
  hocon = «lambda format @ /home/matt/nixpkgs/pr/pkgs/pkgs-lib/formats/hocon/default.nix:35:5»;
  ini = «lambda ini @ /home/matt/nixpkgs/pr/pkgs/pkgs-lib/formats.nix:221:11»;
  iniWithGlobalSection = «lambda iniWithGlobalSection @ /home/matt/nixpkgs/pr/pkgs/pkgs-lib/formats.nix:260:11»;
  javaProperties = «lambda javaProperties @ /home/matt/nixpkgs/pr/pkgs/pkgs-lib/formats/java-properties/default.nix:17:5»;
  json = «lambda json @ /home/matt/nixpkgs/pr/pkgs/pkgs-lib/formats.nix:89:5»;
  keyValue = «lambda keyValue @ /home/matt/nixpkgs/pr/pkgs/pkgs-lib/formats.nix:355:5»;
  libconfig = «lambda format @ /home/matt/nixpkgs/pr/pkgs/pkgs-lib/formats/libconfig/default.nix:30:5»;
  lua = «lambda lua @ /home/matt/nixpkgs/pr/pkgs/pkgs-lib/formats.nix:737:5»;
  php = «lambda format @ /home/matt/nixpkgs/pr/pkgs/pkgs-lib/formats/php/default.nix:5:5»;
  pythonVars = «lambda pythonVars @ /home/matt/nixpkgs/pr/pkgs/pkgs-lib/formats.nix:799:5»;
  systemd = { ... };
  toml = «lambda toml @ /home/matt/nixpkgs/pr/pkgs/pkgs-lib/formats.nix:413:5»;
  xml = «lambda xml @ /home/matt/nixpkgs/pr/pkgs/pkgs-lib/formats.nix:856:5»;
  yaml = «lambda yaml_1_1 @ /home/matt/nixpkgs/pr/pkgs/pkgs-lib/formats.nix:131:5»;
  yaml_1_1 = «lambda yaml_1_1 @ /home/matt/nixpkgs/pr/pkgs/pkgs-lib/formats.nix:131:5»;
}

nix-repl> builtins.removeAttrs fmt (builtins.attrNames used)
{ }

Concerningly, some of the matches you had do not actually exist, although that's unrelated to this PR:

nix-repl> builtins.removeAttrs used (builtins.attrNames fmt)
{
  add_parser = null;
  asn1 = null;
  c = null;
  dataclass = null;
  local_stream = null;
  native_file = null;
  nix = null;
  nrbf = null;
  passthru = null;
  png = null;
  sndfile = null;
  text = null;
  tone_stream = null;
}

Hopefully most of those are false-positives for your regex 🤞

[philiptaron]

Looking at #166044, javaProperties is intentional.

No, no, these are the ones that are used, not the ones that aren't used. Apologies for the confusion.

[MattSturgeon]

Looking at #166044, javaProperties is intentional.

No, no, these are the ones that are used, not the ones that aren't used. Apologies for the confusion.

Gotcha. In that case I think this PR covers them all:

nix-repl> builtins.removeAttrs fmt (builtins.attrNames used)
{ }

[MattSturgeon]

I'm assuming this is niche/internal enough that we don't need to add a release note?

[philiptaron]

Thanks for fixing this mistake of mine.

[philiptaron]

There's a CI failure about aliases here: #415662

😕

[philiptaron]

#415719

[trofi]

Bisect says that this change broke the nixos-rebuild for me. An example nixpkgs test is nixosTests.man:

$ nix build --no-link -f. nixosTests.man -L
...
lazy-options.json>            42| in
lazy-options.json>            43| lib.optionalAttrs pkgs.config.allowAliases aliases
lazy-options.json>              |                   ^
lazy-options.json>            44| // rec {
lazy-options.json>
lazy-options.json>        error: expected a set but found null: null
lazy-options.json> Cacheable portion of option doc build failed.

#415719 proposed by Philip does fix the failure for me when applied to master.