bug: E127 Cannot redefine function

[dimbleby]

Did you check docs and existing issues?

• I have read all the lazy docs
• I have searched the existing issues of lazy
• I have searched the exsiting issues of the plugin I have a problem with

Neovim version (nvim -v)

NVIM v0.9.0-dev-580+g4703e561d

Operating system/version

Ubuntu 22.0.4

Describe the bug

When using fzf-lua's previewer to search for text that appears in a rust file (EDIT or just when opening a rust file, see follow-up comment):

Failed to source `/home/dch/.local/share/nvim/lazy/rust.vim/ftdetect/rust.vim`
...local/share/nvim/lazy/lazy.nvim/lua/lazy/core/loader.lua:303: Vim(function):E127: Cannot redefine function <SNR>5_set_rust_filetype: It is in use
# stacktrace:
  - /fzf-lua/lua/fzf-lua/previewer/builtin.lua:589
  - /fzf-lua/lua/fzf-lua/previewer/builtin.lua:588 _in_ **do_syntax**
  - /fzf-lua/lua/fzf-lua/previewer/builtin.lua:661 _in_ **preview_buf_post**
  - /fzf-lua/lua/fzf-lua/previewer/builtin.lua:538 _in_ ****
  - vim/_editor.lua:0

which seems surprising, rust.vim goes function!, I thought I understood that the meaning of the exclamation mark was exactly to make this not happen

I'm experimenting with the switch from packer to lazy.nvim, and still have a computer with the packer setup - and can confirm that the problem does not reproduce there. So while I could imagine this turning out to be a bug elsewhere, I'm starting with lazy.nvim.

Steps To Reproduce

1. Have a rust project eg https://github.com/dimbleby/rust-c-ares
2. Open a file eg Cargo.toml
3. fzf-lua live_grep_native() for something eg "metadep". (I've mapped the fzf-lua function to <Leader>r in the repro.lua below)
4. scroll down the preview until you hit a rust file containing that text

Expected Behavior

No errors

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",
    "--single-branch",
    "https://github.com/folke/lazy.nvim.git",
    lazypath,
  })
end
vim.opt.runtimepath:prepend(lazypath)

-- install plugins
local plugins = {
  "folke/tokyonight.nvim",
  { "rust-lang/rust.vim", ft = "rust" },
  {
    "ibhagwan/fzf-lua",
    lazy = true,
    config = function()
      require("fzf-lua").setup({})
    end,
  },
}
require("lazy").setup(plugins, {
  root = root .. "/plugins",
})

vim.cmd.colorscheme("tokyonight")

vim.keymap.set("n", "<Leader>r", function()
  require("fzf-lua").live_grep_native()
end, { noremap = true })

[dimbleby]

oh actually I seem to be able to reproduce this error without involving fzf-lua at all: just opening a rust file is enough.

so that simplifies the repro, you can remove all fzf-lua related bits

Failed to source `/home/dch/rust-c-ares/.repro//plugins/rust.vim/ftdetect/rust.vim`
...c-ares/.repro/plugins/lazy.nvim/lua/lazy/core/loader.lua:303: Vim(function):E127: Cannot redefine function <SNR>4_set_rust_filetype: It is in use