Error executing vim.schedule lua callback: async.lua:76: The coroutine failed with this message: vim/shared.lua:0: Expected table, got nil

[benjaminchristie]

Description

This message appears randomly and I often cannot repeat it. It appears when executing the GitSignsUpdate autocmd.

Attached is the traceback from running nvim -V20log, then splitting to a tracked file using vsp:

Executing User Autocommands for "GitSignsUpdate"
autocommand <Lua 321: ~/.config/nvim/plugin/path/to/autocmd.lua>

chdir(/path/to/opened/file)
chdir(/path/to/.config/nvim/plugin/)
chdir(/path/to/opened/file)
Executing: 
           Error executing vim.schedule lua callback: .../share/nvim/plugged/gitsigns.nvim/lua/gitsigns/async.lua:76: The coroutine failed with this message: vim/shared.lua:0: Expected table, got nil
stack traceback:
	[C]: in function 'assert'
	vim/shared.lua: in function 'tbl_isempty'
	...are/nvim/plugged/gitsigns.nvim/lua/gitsigns/diff_int.lua:72: in function 'run_diff'
	...hare/nvim/plugged/gitsigns.nvim/lua/gitsigns/manager.lua:424: in function 'fn'
	...are/nvim/plugged/gitsigns.nvim/lua/gitsigns/debounce.lua:76: in function 'update'
	...share/nvim/plugged/gitsigns.nvim/lua/gitsigns/attach.lua:365: in function 'fn'
	...are/nvim/plugged/gitsigns.nvim/lua/gitsigns/debounce.lua:76: in function 'attach_throttled'
	...share/nvim/plugged/gitsigns.nvim/lua/gitsigns/attach.lua:426: in function <...share/nvim/plugged/gitsigns.nvim/lua/gitsigns/attach.lua:425>
stack traceback:
	[C]: in function 'error'
	.../share/nvim/plugged/gitsigns.nvim/lua/gitsigns/async.lua:76: in function 'cb'
	.../share/nvim/plugged/gitsigns.nvim/lua/gitsigns/async.lua:113: in function 'cb'
	.../share/nvim/plugged/gitsigns.nvim/lua/gitsigns/async.lua:186: in function <.../share/nvim/plugged/gitsigns.nvim/lua/gitsigns/async.lua:184>

Neovim version

NVIM v0.10.0-dev-1035+g65d337800 \ Build type: Release \ LuaJIT 2.1.1693350652

Operating system and version

Linux 6.4.12-arch1-1

Expected behavior

I expect this error to not occur.

Actual behavior

See attached traceback. Note that after refreshing the file, the traceback does not reappear.

Minimal config

for name, url in pairs{
  gitsigns = 'https://github.com/lewis6991/gitsigns.nvim',
  -- ADD OTHER PLUGINS _NECESSARY_ TO REPRODUCE THE ISSUE
} do
  local install_path = vim.fn.fnamemodify('gitsigns_issue/'..name, ':p')
  if vim.fn.isdirectory(install_path) == 0 then
    vim.fn.system { 'git', 'clone', '--depth=1', url, install_path }
  end
  vim.opt.runtimepath:append(install_path)
end

require('gitsigns').setup{
  debug_mode = true, -- You must add this to enable debug messages
  -- ADD GITSIGNS CONFIG THAT IS _NECESSARY_ FOR REPRODUCING THE ISSUE
}

-- ADD INIT.LUA SETTINGS THAT IS _NECESSARY_ FOR REPRODUCING THE ISSUE
vim.api.nvim_create_autocmd('User', {
    pattern = 'GitSignsUpdate',
    callback = function()
         local branch = vim.b.gitsigns_head
         if branch ~= nil then
              local hunks_tb = gitsigns.get_hunks(vim.api.nvim_get_current_buf())
              if hunks_tb ~= nil then
                   print(vim.inspect(hunks_tb))
              end
         end
    end
})

Steps to reproduce

1. nvim --clean -u minimal.lua
2. open a tracked file using vsp, pray that this glitch occurs as it seems random

Gitsigns debug messages

No response