Random error in insert mode: buffer.lua:356: bad argument #1 to 'ipairs'

[Michael Härtl]

I randomly see the same error as described in the closed issue #33

Error executing vim.schedule lua callback: .../share/nvim/plugged/cmp-buffer/lua/cmp_buffer/buffer.lua:356: bad argument #1 to 'ipairs' (table expecte
d, got userdata)                                                                                                                                      
stack traceback:                                                                                                                                      
        [C]: in function 'ipairs'                                                                                                                     
        .../share/nvim/plugged/cmp-buffer/lua/cmp_buffer/buffer.lua:356: in function 'rebuild_unique_words'                                           
        .../share/nvim/plugged/cmp-buffer/lua/cmp_buffer/buffer.lua:342: in function 'get_words'                                                      
        .../share/nvim/plugged/cmp-buffer/lua/cmp_buffer/source.lua:66: in function 'fn'                                                              
        vim/_editor.lua:380: in function 'cb'                                                                                                         
        vim/_editor.lua:256: in function <vim/_editor.lua:256>

I can not provide a way to reproduce.

My relevant config (nvim 0.7.0):

" LSP (Intellisense / Autocomplete)
Plug 'neovim/nvim-lspconfig'        " Start LSP server on demand
Plug 'hrsh7th/nvim-cmp'             " Autocomplete
Plug 'hrsh7th/cmp-buffer'           " Buffer word completion source for nvim-cmp
Plug 'hrsh7th/cmp-cmdline'          " Command line / search completions
Plug 'hrsh7th/cmp-nvim-lsp'         " LSP completion source for nvim-cmp
Plug 'hrsh7th/cmp-nvim-lua'         " LUA completion source for nvim-cmp
Plug 'hrsh7th/cmp-nvim-lsp-signature-help'            " LSP function signature
Plug 'hrsh7th/cmp-path'             " Path completion source for nvim-cmp
Plug 'hrsh7th/cmp-vsnip'            " vsnip completion source for nvim-cmp
Plug 'hrsh7th/vim-vsnip'            " Snippets plugin
Plug 'rafamadriz/friendly-snippets', { 'branch': 'main' } " Snippets collection

lua <<EOF

  --
  -- For breaking changes see: https://github.com/hrsh7th/nvim-cmp/issues/231
  --

  local cmp = require'cmp'

  -- Check if there's a word before the cursor (used by <TAB> mapping)
  local has_words_before = function()
    local line, col = unpack(vim.api.nvim_win_get_cursor(0))
    return col ~= 0 and vim.api.nvim_buf_get_lines(0, line - 1, line, true)[1]:sub(col, col):match("%s") == nil
  end

  -- Send feed keys with special codes (used by <S-TAB> mapping)
  local feedkey = function(key, mode)
    vim.api.nvim_feedkeys(vim.api.nvim_replace_termcodes(key, true, true, true), mode, true)
  end

  cmp.setup({
    -- Configure snippet engine
    snippet = {
      expand = function(args)
        -- We use vim-vsnip
        vim.fn["vsnip#anonymous"](args.body)
      end,
    },
    -- :h cmp-mapping
    mapping = {
      -- Navigate up/down (i, c: insert & command line mode)
      ['<C-j>'] = cmp.mapping(cmp.mapping.select_next_item(), {'i', 'c'}),
      ['<C-k>'] = cmp.mapping(cmp.mapping.select_prev_item(), {'i', 'c'}),

      -- Open / close completion menu
      ['<C-Space>'] = cmp.mapping.complete(),
      ['<C-e>'] = cmp.mapping.abort(),

      ['<C-d>'] = cmp.mapping.scroll_docs(-4),
      ['<C-f>'] = cmp.mapping.scroll_docs(4),

      ['<CR>'] = cmp.mapping.confirm({ select = false }),
      -- Make Tab/S-Tab behave context sensitive
      ["<Tab>"] = cmp.mapping(function(fallback)
        if cmp.visible() then
          cmp.select_next_item()
        elseif vim.fn["vsnip#available"]() == 1 then
          feedkey("<Plug>(vsnip-expand-or-jump)", "")
        elseif has_words_before() then
          cmp.complete()
        else
          fallback() -- The fallback function sends a already mapped key. In this case, it's probably `<Tab>`.
        end
      end, { "i", "s" }),
      ["<S-Tab>"] = cmp.mapping(function()
        if cmp.visible() then
          cmp.select_prev_item()
        elseif vim.fn["vsnip#jumpable"](-1) == 1 then
          feedkey("<Plug>(vsnip-jump-prev)", "")
        end
      end, { "i", "s" }),

    },
    sources = cmp.config.sources({
      { name = 'nvim_lsp' },
      { name = 'vsnip' },
      {
          name = 'buffer',
          option = {
            -- complete from all buffers
            get_bufnrs = function()
              return vim.api.nvim_list_bufs()
            end
          },
      },
      { name = 'nvim_lua' },
      { name = 'nvim_lsp_signature_help' },
      { name = 'path' },
    }),
    formatting = {
      format = require("lspkind").cmp_format({
        with_text = true,
        menu = ({
          buffer = "[Buffer]",
          nvim_lsp = "[LSP]",
          vsnip = "[Vsnip]",
          nvim_lua = "[Lua]",
          path = "[Path]",
        })
      }),
    },
  })
  -- Completion for :commands
  cmp.setup.cmdline(':', {
    sources = {
      { name = 'cmdline' }
    }
  })
  -- Completion for /search based on current buffer
  cmp.setup.cmdline('/', {
    sources = cmp.config.sources({
      { name = 'buffer' }
    })
  })

local lspconfig = require'lspconfig'
local cmp_nvim_lsp = require'cmp_nvim_lsp'

-- Set global defaults for all servers
lspconfig.util.default_config = vim.tbl_extend(
  "force",
  lspconfig.util.default_config,
  {
    -- Required by nvim-cmp
    capabilities = cmp_nvim_lsp.update_capabilities(vim.lsp.protocol.make_client_capabilities()),
  }
)
EOF

[Breno]

I get something similar. Using Windows 10 here.

Error executing vim.schedule lua callback: ...\Local\nvim\plugged\cmp-buffer/lua/cmp_buffer/buffer.lua:356: bad argument #1 to 'ipairs' (table expected, got userdata)
stack traceback:
        [C]: in function 'ipairs'
        ...\Local\nvim\plugged\cmp-buffer/lua/cmp_buffer/buffer.lua:356: in function 'rebuild_unique_words'
        ...\Local\nvim\plugged\cmp-buffer/lua/cmp_buffer/buffer.lua:341: in function 'get_words'
        ...\Local\nvim\plugged\cmp-buffer/lua/cmp_buffer/source.lua:66: in function 'fn'
        vim/_editor.lua:380: in function 'cb'
        vim/_editor.lua:256: in function <vim/_editor.lua:256>

It seems to only appear when I type on a dap-repl buffer, which is a debugger console from mfussenegger/nvim-dap.

It's a shame the callback does not indicate anything wrong in config.lua.