Error with lazy loading via cmd options

[garymh]

This still seems to be happening to me with the latest Packer 😞

While running :Switch, which should be lazy loaded, I get:

Error in packer_compiled: ...vim/site/pack/packer/opt/packer.nvim/lua/packer/load.lua:10: attempt to index local 'plugin' (a nil value)
Please check your config for correctness

Here is my packer loading code:

local packer = nil

local function init()
    if packer == nil then
        packer = require('packer')
        util = require("packer/util")
        packer.init({
            compile_path = util.join_paths(vim.fn.stdpath("config"),
                                           "vimscript", "packer_compiled.vim"),
            max_jobs = 10
        })
    end

    local use = packer.use
    packer.reset()

    use {"wbthomason/packer.nvim", opt = true}

    use {
        "AndrewRadev/switch.vim",
        cmd = {"Switch", "SwitchReverse"},
        config = function()
            vim.g.switch_custom_definitions =
                {
                    {"assert", "refute"}, {"if", "unless"}, {"[ ]", "[x]"},
                    {"yes", "no"}, {"let g:", "vim.g."}
                }
        end
    }
end

local plugins = setmetatable({}, {
    __index = function(_, key)
        init()
        return packer[key]
    end
})

return plugins

Originally posted by @garymh in #180 (comment)

[garymh]

init.lua for reference as well:

require 'plugins'

vim.api.nvim_command [[ augroup auto_compile ]]
vim.api.nvim_command [[ autocmd! ]]
vim.api.nvim_command [[ autocmd BufWritePost plugins.lua PackerCompile ]]
vim.api.nvim_command [[ augroup END ]]
vim.cmd [[source $HOME/.config/nvim/vimscript/packer_compiled.vim]]

[wbthomason]

@garymh Thanks for the report! I'm having trouble reproducing this - using your switch specification, the :Switch command works as expected. Can you please post your compiled file?

[garymh]

@wbthomason Thanks for reading it! 😄

🤔 Hmm. That's odd! It must be something screwy with my setup. Here's the compiled file:

" Automatically generated packer.nvim plugin loader code

if !has('nvim-0.5')
  echohl WarningMsg
  echom "Invalid Neovim version for packer.nvim!"
  echohl None
  finish
endif

packadd packer.nvim

try

lua << END
  local time
  local profile_info
  local should_profile = false
  if should_profile then
    local hrtime = vim.loop.hrtime
    profile_info = {}
    time = function(chunk, start)
      if start then
        profile_info[chunk] = hrtime()
      else
        profile_info[chunk] = (hrtime() - profile_info[chunk]) / 1e6
      end
    end
  else
    time = function(chunk, start) end
  end
  
local function save_profiles(threshold)
  local sorted_times = {}
  for chunk_name, time_taken in pairs(profile_info) do
    sorted_times[#sorted_times + 1] = {chunk_name, time_taken}
  end
  table.sort(sorted_times, function(a, b) return a[2] > b[2] end)
  local results = {}
  for i, elem in ipairs(sorted_times) do
    if not threshold or threshold and elem[2] > threshold then
      results[i] = elem[1] .. ' took ' .. elem[2] .. 'ms'
    end
  end

  _G._packer = _G._packer or {}
  _G._packer.profile_output = results
end

time("Luarocks path setup", true)
local package_path_str = "/Users/gary/.cache/nvim/packer_hererocks/2.1.0-beta3/share/lua/5.1/?.lua;/Users/gary/.cache/nvim/packer_hererocks/2.1.0-beta3/share/lua/5.1/?/init.lua;/Users/gary/.cache/nvim/packer_hererocks/2.1.0-beta3/lib/luarocks/rocks-5.1/?.lua;/Users/gary/.cache/nvim/packer_hererocks/2.1.0-beta3/lib/luarocks/rocks-5.1/?/init.lua"
local install_cpath_pattern = "/Users/gary/.cache/nvim/packer_hererocks/2.1.0-beta3/lib/lua/5.1/?.so"
if not string.find(package.path, package_path_str, 1, true) then
  package.path = package.path .. ';' .. package_path_str
end

if not string.find(package.cpath, install_cpath_pattern, 1, true) then
  package.cpath = package.cpath .. ';' .. install_cpath_pattern
end

time("Luarocks path setup", false)
time("try_loadstring definition", true)
local function try_loadstring(s, component, name)
  local success, result = pcall(loadstring(s))
  if not success then
    print('Error running ' .. component .. ' for ' .. name)
    error(result)
  end
  return result
end

time("try_loadstring definition", false)
time("Defining packer_plugins", true)
_G.packer_plugins = {
  ["packer.nvim"] = {
    loaded = false,
    needs_bufread = false,
    path = "/Users/gary/.local/share/nvim/site/pack/packer/opt/packer.nvim"
  },
  ["switch.vim"] = {
    commands = { "Switch", "SwitchReverse" },
    config = { "\27LJ\2\n§\2\0\0\3\0\n\0\0196\0\0\0009\0\1\0004\1\b\0005\2\3\0>\2\1\0015\2\4\0>\2\2\0015\2\5\0>\2\3\0015\2\6\0>\2\4\0015\2\a\0>\2\5\0015\2\b\0>\2\6\0015\2\t\0>\2\a\1=\1\2\0K\0\1\0\1\2\0\0005expect(\\([^. ]\\+\\))\\.to\\(_not\\|\\)': '\\1.should\\2\1\2\0\0006\\([^. ]\\+\\)\\.should\\(_not\\|\\)': 'expect(\\1)\\.to\\2\1\3\0\0\vlet g:\vvim.g.\1\3\0\0\byes\ano\1\3\0\0\b[ ]\b[x]\1\3\0\0\aif\vunless\1\3\0\0\vassert\vrefute\30switch_custom_definitions\6g\bvim\0" },
    loaded = false,
    needs_bufread = true,
    path = "/Users/gary/.local/share/nvim/site/pack/packer/opt/switch.vim"
  }
}

time("Defining packer_plugins", false)

-- Command lazy-loads
time("Defining lazy-load commands", true)
vim.cmd [[command! -nargs=* -range -bang -complete=file Switch lua require("packer.load")({'switch.vim'}, { cmd = "Switch", l1 = <line1>, l2 = <line2>, bang = <q-bang>, args = <q-args> }, _G.packer_plugins)]]
vim.cmd [[command! -nargs=* -range -bang -complete=file SwitchReverse lua require("packer.load")({'switch.vim'}, { cmd = "SwitchReverse", l1 = <line1>, l2 = <line2>, bang = <q-bang>, args = <q-args> }, _G.packer_plugins)]]
time("Defining lazy-load commands", false)

if should_profile then save_profiles() end

END

catch
  echohl ErrorMsg
  echom "Error in packer_compiled: " .. v:exception
  echom "Please check your config for correctness"
  echohl None
endtry

``

[garymh]

If it helps any, here it is without the lazy loaded commands:

" Automatically generated packer.nvim plugin loader code

if !has('nvim-0.5')
  echohl WarningMsg
  echom "Invalid Neovim version for packer.nvim!"
  echohl None
  finish
endif

packadd packer.nvim

try

lua << END
  local time
  local profile_info
  local should_profile = false
  if should_profile then
    local hrtime = vim.loop.hrtime
    profile_info = {}
    time = function(chunk, start)
      if start then
        profile_info[chunk] = hrtime()
      else
        profile_info[chunk] = (hrtime() - profile_info[chunk]) / 1e6
      end
    end
  else
    time = function(chunk, start) end
  end
  
local function save_profiles(threshold)
  local sorted_times = {}
  for chunk_name, time_taken in pairs(profile_info) do
    sorted_times[#sorted_times + 1] = {chunk_name, time_taken}
  end
  table.sort(sorted_times, function(a, b) return a[2] > b[2] end)
  local results = {}
  for i, elem in ipairs(sorted_times) do
    if not threshold or threshold and elem[2] > threshold then
      results[i] = elem[1] .. ' took ' .. elem[2] .. 'ms'
    end
  end

  _G._packer = _G._packer or {}
  _G._packer.profile_output = results
end

time("Luarocks path setup", true)
local package_path_str = "/Users/gary/.cache/nvim/packer_hererocks/2.1.0-beta3/share/lua/5.1/?.lua;/Users/gary/.cache/nvim/packer_hererocks/2.1.0-beta3/share/lua/5.1/?/init.lua;/Users/gary/.cache/nvim/packer_hererocks/2.1.0-beta3/lib/luarocks/rocks-5.1/?.lua;/Users/gary/.cache/nvim/packer_hererocks/2.1.0-beta3/lib/luarocks/rocks-5.1/?/init.lua"
local install_cpath_pattern = "/Users/gary/.cache/nvim/packer_hererocks/2.1.0-beta3/lib/lua/5.1/?.so"
if not string.find(package.path, package_path_str, 1, true) then
  package.path = package.path .. ';' .. package_path_str
end

if not string.find(package.cpath, install_cpath_pattern, 1, true) then
  package.cpath = package.cpath .. ';' .. install_cpath_pattern
end

time("Luarocks path setup", false)
time("try_loadstring definition", true)
local function try_loadstring(s, component, name)
  local success, result = pcall(loadstring(s))
  if not success then
    print('Error running ' .. component .. ' for ' .. name)
    error(result)
  end
  return result
end

time("try_loadstring definition", false)
time("Defining packer_plugins", true)
_G.packer_plugins = {
  ["packer.nvim"] = {
    loaded = false,
    needs_bufread = false,
    path = "/Users/gary/.local/share/nvim/site/pack/packer/opt/packer.nvim"
  },
  ["switch.vim"] = {
    config = { "\27LJ\2\n§\2\0\0\3\0\n\0\0196\0\0\0009\0\1\0004\1\b\0005\2\3\0>\2\1\0015\2\4\0>\2\2\0015\2\5\0>\2\3\0015\2\6\0>\2\4\0015\2\a\0>\2\5\0015\2\b\0>\2\6\0015\2\t\0>\2\a\1=\1\2\0K\0\1\0\1\2\0\0005expect(\\([^. ]\\+\\))\\.to\\(_not\\|\\)': '\\1.should\\2\1\2\0\0006\\([^. ]\\+\\)\\.should\\(_not\\|\\)': 'expect(\\1)\\.to\\2\1\3\0\0\vlet g:\vvim.g.\1\3\0\0\byes\ano\1\3\0\0\b[ ]\b[x]\1\3\0\0\aif\vunless\1\3\0\0\vassert\vrefute\30switch_custom_definitions\6g\bvim\0" },
    loaded = true,
    path = "/Users/gary/.local/share/nvim/site/pack/packer/start/switch.vim"
  }
}

time("Defining packer_plugins", false)
-- Config for: switch.vim
time("Config for switch.vim", true)
try_loadstring("\27LJ\2\n§\2\0\0\3\0\n\0\0196\0\0\0009\0\1\0004\1\b\0005\2\3\0>\2\1\0015\2\4\0>\2\2\0015\2\5\0>\2\3\0015\2\6\0>\2\4\0015\2\a\0>\2\5\0015\2\b\0>\2\6\0015\2\t\0>\2\a\1=\1\2\0K\0\1\0\1\2\0\0005expect(\\([^. ]\\+\\))\\.to\\(_not\\|\\)': '\\1.should\\2\1\2\0\0006\\([^. ]\\+\\)\\.should\\(_not\\|\\)': 'expect(\\1)\\.to\\2\1\3\0\0\vlet g:\vvim.g.\1\3\0\0\byes\ano\1\3\0\0\b[ ]\b[x]\1\3\0\0\aif\vunless\1\3\0\0\vassert\vrefute\30switch_custom_definitions\6g\bvim\0", "config", "switch.vim")
time("Config for switch.vim", false)
if should_profile then save_profiles() end

END

catch
  echohl ErrorMsg
  echom "Error in packer_compiled: " .. v:exception
  echom "Please check your config for correctness"
  echohl None
endtry

[wbthomason]

Thanks! Just to confirm, the non-lazy-loaded version does not throw an error?

[garymh]

Correct!

[wbthomason]

Hmm. I'm still unable to reproduce this. Your compiled files look fine too...

I've pushed a change (in 87980fc) that might help with debugging, if you can give a try. From your error message, it looks like the plugin name we try to load is not present in the table of plugins (just to check, you don't modify _G.packer_plugins anywhere in your config, right?), so the change will check that an attempted load is present and print its name/exit with an error if it is not.

[garymh]

Sure! I got:

Error: attempted to load switch.vim which is not present in plugins table!
Error in packer_compiled: ...vim/site/pack/packer/opt/packer.nvim/lua/packer/load.lua:14: Error: attempte
d to load switch.vim which is not present in plugins table!
Please check your config for correctness

I haven't modified _G.packer_plugins at all. I don't think there are any other files being loaded besides some tiny random syntax ones (that just adjust vim options)

[garymh]

AH! I just realized what it was... I actually had a plugin/packer_compiled.vim file in my config folder in addition to the one I was manually loading. Removed the first file and it works fine! 🤦

[garymh]

It might be handy for debugging to put a check if it tries to load packer twice, though!

[garymh]

Thanks again for the support, though! 😄

[wbthomason]

Ah, whoops. That'd do it! Thanks! Unfortunately naively detecting if loading packer twice is desired or not is tricky; the user may re-source their compiled file during normal use. However, we should probably add a check to make sure that it's the same file path.