error "No plugins are available to handle this SMethod_TextDocumentInlayHint request" on every input

[leana8959]

Neovim version (nvim -v)

v0.11.2

Operating system/version

NixOS 25.05

Output of :checkhealth haskell-tools

Checking for Lua dependencies ~
- ⚠️ WARNING telescope not installed. Required for hoogle search modes "telescope-local" and "telescope-web" [nvim-telescope/telescope.nvim](https://github.com/nvim-telescope/telescope.nvim)

Checking external dependencies ~
- ✅ OK haskell-language-server: found haskell-language-server version: 2.10.0.0 (GHC: 9.8.4) (PATH: /nix/store/24jiyk0jzs3vx9qpph7cgnvqkaf0dyn3-haskell-language-server-2.10.0.0/bin/haskell-language-server-wrapper)
- ⚠️ WARNING hoogle: not found.
    Install [ndmitchell/hoogle](https://github.com/ndmitchell/hoogle) for extended capabilities.
          Recommended for better Hoogle search performance.
    Without a local installation, the web API will be used by default.
    Required if the hoogle mode is set to "telescope-local".
  
    
- ⚠️ WARNING fast-tags: not found.
  Install [fast-tags](https://hackage.haskell.org/package/fast-tags) for extended capabilities.
  Optional, for generating tags as a `tagfunc` fallback.
  
- ✅ OK curl: found curl 8.13.0 (x86_64-pc-linux-gnu) libcurl/8.13.0 OpenSSL/3.4.1 zlib/1.3.1 brotli/1.1.0 zstd/1.5.7 libidn2/2.3.8 libpsl/0.21.5 libssh2/1.11.1 nghttp2/1.65.0
- ⚠️ WARNING haskell-debug-adapter: not found.
  Install [haskell-debug-adapter](https://github.com/phoityne/haskell-debug-adapter) for extended capabilities.
  Optional, for `dap` support.
  
- ⚠️ WARNING ghci-dap: not found.
  Install [ghci-dap](https://github.com/phoityne/ghci-dap) for extended capabilities.
  Optional, for `dap` support.
  

Checking config ~
- ✅ OK No errors found in config.

Checking for conflicting plugins ~
- ✅ OK No conflicting plugins detected.

How to reproduce the issue

• Write the following config to $XDG_CONFIG/haskell-tools.nvim/init.lua

• Clone this template repository https://github.com/leana8959/ht-tools-repr with basic nix shell support and a simple haskell project

• Run NVIM_APPNAME="haskell-tools.nvim" nvim simple.cabal

• Wait a brief moment and the following error should spawn.

  Inserting any text would trigger the same error over and over again.

  haskell-tools.nvim (cabal): -32601: No plugins are available to handle this SMethod_TextDocumentInlayHint request.
   Plugins installed for this method, but not available to handle this request are:
  explicit-fields does not support .cabal filetypes).
  importLens does not support .cabal filetypes).
  

Expected behaviour

neovim should not spawn this much error, if at all.

Actual behaviour

Getting the aforementioned error.

Log files

https://gist.github.com/leana8959/55b699009f7efba29aa1955c5d2ca272

The minimal config used to reproduce this issue.

-- Sorry I had to deactivate this, for some reason this makes neovim spawn another unrelated error 99% of the time.
-- vim.env.LAZY_STDPATH = ".repro"
load(vim.fn.system("curl -s https://raw.githubusercontent.com/folke/lazy.nvim/main/bootstrap.lua"))()

require("lazy.minit").repro {
    spec = {
        {
            "mrcjkb/haskell-tools.nvim",
            version = "^6",
            init = function()
                -- Enable inlay hints
                vim.lsp.inlay_hint.enable()
                vim.g.haskell_tools = {}
            end,
            lazy = false,
        },
    },
}

[mrcjkb]

Hey 👋

This isn't a bug. Haskell-language-server doesn't support inlay hints for cabal files (or at all, afaik).
I recommend you use an LspAttach autocommand or the on_attach function in your config to check if inlay hints are supported by the client and only enable them if they are:

Here's how I do it in my config:

https://github.com/mrcjkb/nvim/blob/12514c73e08a40f9b20181c54edbca9722aaf722/nvim/plugin/autocommands.lua#L298

[mrcjkb]

Yes, you could probably also enable it for cabal files.
But again, as far as I'm aware, hls doesn't support inlay hints for Haskell files yet, either.

[mrcjkb]

haskell/haskell-language-server#2938

[leana8959]

Hmm, maybe that thread is not entirely up to date?
I'm getting inlay hints for multiple different aspects in neovim.

Here's one example of it showing the fields of a record.

[mrcjkb]

Hmm, I guess it was added recently.
I'm that case, yes I would add an exclusion for cabal files.
Hls doesn't support all features for cabal files, but reports them as supported (because it supports them for Haskell files).
Haskell-tools spawns separate clients for Haskell and cabal files to minimise issues. But since inlay hints have to be enabled manually, it's up to the user to perform the appropriate checks.

[leana8959]

I see, thank you so much!