Moving to init.lua on Neovim 0.11 and the E5422 Config Conflict

I migrated the NeoVim configuration I set up in Reviewing my Zsh and NeoVim configuration over to Lua.

TL;DR

• Neovim 0.11.5 assumes Lua, so moving from init.vim + vim-plug toward init.lua + lazy.nvim gives you a big return.
• For completion, blink.cmp is a strong choice these days.
• The 0.11 trap: init.lua and init.vim cannot live side by side (E5422: Conflicting configs). A staged migration takes some ingenuity.
• While I was at it: NERDTree→oil.nvim, hand-written brackets→nvim-autopairs, IME→Lua autocmd, cursor shape→guicursor.

Background

In the Neovim 0.11 generation, the ecosystem of LSP, diagnostics and the surrounding plugins moves ahead on the premise of Lua. If you keep maintaining a Vimscript-centred setup,

• you get little benefit from the new configuration APIs
• the gap with the plugins’ samples and documentation keeps widening
• narrowing things down when there is trouble gets slower

and you end up in that kind of slow, creeping defeat.

The 0.11 pitfall: init.lua and init.vim cannot coexist

On 0.11, if ~/.config/nvim/init.lua and ~/.config/nvim/init.vim exist at the same time, startup stops with E5422: Conflicting configs.

In other words, the classic plan of “create init.lua, source init.vim from it, and migrate in stages” falls apart as it is.

Where I landed this time:

• Throw away init.vim (delete it on the repo side too)
• Port the behaviour I need over to Lua
• The legacy.vim used for temporary stashing was in the end emptied out and deleted

Structure

• nvim/init.lua: the entry point (lazy bootstrap + loading core)
• nvim/lua/plugins.lua: where the lazy.nvim specs are collected
• nvim/lua/core/options.lua: options / guicursor / IME autocmd
• nvim/lua/core/keymaps.lua: keymaps
• nvim/lua/core/diagnostics.lua: diagnostic settings + LspAttach

Key points of the implementation

1) Bootstrapping lazy.nvim in init.lua

• Clone lazy.nvim if it is not there
• Load core/* and plugins
• A simple hot reload that re-reads the Lua on save

2) Plugins managed by lazy.nvim

• telescope.nvim
• nvim-treesitter
• copilot.lua
• CopilotChat.nvim
• blink.cmp
• nvim-lspconfig (passes blink’s capabilities to the LSP)

And to bring legacy down to zero:

• oil.nvim (NERDTree replacement)
• nvim-autopairs (replacement for the hand-written bracket completion)

3) Settings that pay off on 0.11 (diagnostic/LspAttach)

• Spell out vim.diagnostic.config in Lua
• Buffer-local keymaps on LspAttach (hover/definition/rename/code action/diagnostic nav/format)

4) Bringing legacy to zero (Oil/Autopairs/IME/Cursor)

• NERDTree→Oil: assign <C-t> to :Oil and the migration cost is zero
• Bracket completion: stop the hand-written inoremap and use nvim-autopairs
• Cursor shape: stop the t_SI/t_EI hack and use guicursor
• IME: call im-select from a Lua autocmd (asynchronously with vim.system() in 0.11)

5) The <Tab> problem (Copilot vs completion)

<Tab> tends to collide between Copilot, the completion UI and the pum.

This time I settled on the behaviour of “accept with <Tab> only while a Copilot ghost suggestion is visible, and fall back to the pum or a normal Tab otherwise”.

Operational cleanup (the junk that tends to be left behind after migrating)

• Delete the old copilot.vim (~/.config/nvim/pack/...) to avoid double loading
• Delete ~/.config/nvim/plugged/ (the vim-plug leftovers) too
• Delete the broken ~/.vimrc symlink as well (a source of noise when Vim starts)

See also