bug: Update action fails if GIT_DIR environment variable is defined

[pedropombeiro]

Did you check docs and existing issues?

• I have read all the lazy.nvim docs
• I have searched the existing issues of lazy.nvim
• I have searched the exsiting issues of plugins related to this issue

Neovim version (nvim -v)

NVIM v0.8.2 Build type: Release LuaJIT 2.1.0-beta3 Compiled by brew@Ventura-arm64.local

Operating system/version

MacOS 13.1

Describe the bug

When editing files on my dotfiles repo, I have GIT_DIR defined to make it simple to connect to my git repo which is in a different directory. When I switched from Packer to Lazy.nvim, I stopped being able to update plugins unless the GIT_DIR environment variable was unset because Lazy.nvim is calling git and git is picking up on GIT_DIR. We should probably unset GIT_DIR on the forked git process.

Steps To Reproduce

1. Export a GIT_DIR environment variable
2. Enter Neovim
3. Run :Lazy sync

Expected Behavior

I expect the plugins to update correctly.

Repro

-- DO NOT change the paths and don't remove the colorscheme
local root = vim.fn.fnamemodify("./.repro", ":p")

-- set stdpaths to use .repro
for _, name in ipairs({ "config", "data", "state", "cache" }) do
  vim.env[("XDG_%s_HOME"):format(name:upper())] = root .. "/" .. name
end

-- bootstrap lazy
local lazypath = root .. "/plugins/lazy.nvim"
if not vim.loop.fs_stat(lazypath) then
  vim.fn.system({ "git", "clone", "--filter=blob:none", "https://github.com/folke/lazy.nvim.git", lazypath, })
end
vim.opt.runtimepath:prepend(lazypath)

-- install plugins
local plugins = {
  "folke/tokyonight.nvim",
  -- add any other plugins here
}
require("lazy").setup(plugins, {
  root = root .. "/plugins",
})

vim.cmd.colorscheme("tokyonight")
-- add anything else here

[pedropombeiro]

Updated and confirmed that the problem is now solved. Thanks for the incredibly quick turnaround time @folke, love Lazy.nvim!

[folke]

You're welcome!