haskell lsp not getting detected

[theNoof]

I have confirmed that this is a bug related to nvf

• This is a bug, and not an user error or a support request. I understand that my issue will be closed if it is not a bug in nvf.
• I have checked the issues tab and confirmed that my issue has not yet been reported. I understand that my issue will be closed if it is a duplicate.

Description

when i open a .hs file, an error message appears:

i press enter and it disappears, and i dont have lsp support

Installation Method

NixOS Module (nixosModules.default)

Installation Method (Other)

No response

nvf Version

master, related flake.lock content:

    "nvf": {
      "inputs": {
        "flake-compat": "flake-compat_5",
        "flake-parts": "flake-parts_2",
        "mnw": "mnw",
        "nixpkgs": [
          "nixpkgs"
        ],
        "systems": "systems_7"
      },
      "locked": {
        "lastModified": 1755463179,
        "narHash": "sha256-5Ggb1Mhf7ZlRgGi2puCa2PvWs6KbMnWBlW6KW7Vf79Y=",
        "owner": "notashelf",
        "repo": "nvf",
        "rev": "03833118267ad32226b014b360692bdce9d6e082",
        "type": "github"
      },
      "original": {
        "owner": "notashelf",
        "repo": "nvf",
        "type": "github"
      }
    },

Reproduction steps

1. enable haskell lsp (with nixpkgs unstable, untested on stable)
2. open a .hs file
3. look at a beatuiful but annoying error message

Expected behavior

the lsp getting found and working without any issues

Actual Behavior

no lsp support, angry error message on startup

System Information

- system: `"x86_64-linux"`
 - host os: `Linux 6.12.42, NixOS, 25.11 (Xantusia), 25.11.20250819.2007595`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.28.4`
 - channels(root): `"nixos-24.11"`
 - nixpkgs: `/nix/store/pxnx7dbr0pz3qpgw2r315wdbb00afdw7-source`

Relevant log output

error message already provided above

[horriblename]

hls is very particular about
the ghc version, so most of the time you'll have to install hls separately, per-project. Just open a nix shell nixpkgs#haskell.packages.ghc984.haskell-language-server and it should work. You probably want to set up a devShell to make things easier next time (or just install it any way you like on your $PATH, your choice)

as an added note, you can set vim.language.haskell.lsp.packages to null to avoid installing a hls version that doesn't work for you

I'm not 100% sure if there's something wrong with our haskell setup, I'll have to double check later