nil.formatting.command setting does not work

[caiigee]

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• Completed

Describe the bug / provide steps to reproduce it

I have declared the Nix language extension in my home-manager options for Zed:

  programs.zed-editor = {
    enable = true;
    extensions = [
      "html"
      "toml"
      "nix"
      "ron"
      "git-firefly"
    ];

I have also declared nil and nixd as extraPackages for Zed:

    extraPackages = with pkgs; [
      nixd
      nil
      alejandra
    ];

Now, when I edit nix files all the syntax highlight and suggestions and all that works. However, when I try to format using Ctrl+Shift+i it gives me an error saying:

2024-12-07T11:00:47.985513761+01:00 [ERROR] Formatting failed: failed to format via language server: No formatter configured. Set the nil.formatting.command LSP server setting.
2024-12-07T11:00:47.985598351+01:00 [ERROR] failed to format via language server

Caused by:
    No formatter configured. Set the nil.formatting.command LSP server setting.

So, that is exactly what I tried:

      lsp = {
        nil = {
          formatting = {
            command = "alejandra .";
          };
        };
      };

However, the above setting doesn't seem to do anything. Did I do something wrong? Is there another that I should have declared?

Environment

Zed: v0.163.2 (Zed)
OS: Linux Wayland nixos 25.05
Memory: 14.9 GiB
Architecture: x86_64
GPU: AMD Radeon 680M (RADV REMBRANDT) || radv || Mesa 24.2.6

If applicable, add mockups / screenshots to help explain present your vision of the feature

No response

If applicable, attach your Zed.log file to this issue.

No response

[thoward27]

Just in case this is helpful to anyone, here's a working zed configuration stanza for the nil lsp:

  "lsp": {
    "nil": {
      "initialization_options": {
        "formatting": {
          "command": ["nixfmt"]
        }
      }
    }
  }

[uncenter]

This works for me (simplified):

{
  programs.zed-editor = {
    enable = true;

    extensions = [
      "nix"
    ];

    userSettings = {
      languages = {
        Nix = {
          language_servers = [
            "nil"
            "!nixd"
          ];
          formatter = {
            external = {
              command = "nixfmt";
            };
          };
        };
      };
    };
  };
}

[notpeter]

Would love to document any/all of these things in the zed-extensions/nix README.md. Happy to review PRs!