Neovim: config update

A few days ago I finally found the courage to update my setup, moving from a single vimscript file to a nice Lua config. I also took the opportunity to update my tmux config.

For at least 10 years, I’ve been using Vim inside tmux with the same prefix, C-w. When Vim is open, the prefix is forwarded to vim; otherwise, it goes to tmux. Life is good, everything works.

Migration fail

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The curse of updates: this behavior is broken. But only partially, meaning that with the combo tmux+neovim or ssh+tmux+neovim on my laptop, everything is fine, BUT on my desktop with tmux+neovim, it isn’t.

Am I a grumpy old man now? Is this it? Is this the feeling? The world changes and I can’t adapt? Not wanting to change my habits so they work with how the world changes?

Probably. I’m a grumpy old man then. I want Ctrl-w as the prefix for tmux and Neovim. Leave me alone with your editors of the future.

Let’s check versions first, and add a third server as a witness for fun.

Okay. We already have a small idea of what’s wrong. I’ll have to manually update tmux and nvim. Once I’ve got a working workflow, I’ll add the required versions to my config’s README.

Update on Manjaro

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On AUR, we can find tmux 3.6:

$ yay -Ss tmux
extra/tmux 3.6_a-1 (485.2 KiB 1.1 MiB) (Installed)
    Terminal multiplexer
$ tmux -V
tmux 3.6a

Same for neovim:

$ yay -Ss neovim
extra/neovim 0.11.5-1 (6.8 MiB 28.8 MiB) (Installed)
    Fork of Vim aiming to improve user experience, plugins, and GUIs
$ nvim --version
NVIM v0.11.5
Build type: RelWithDebInfo
LuaJIT 2.1.1765007043
Run "nvim -V1 -v" for more info

Let’s see if I restart the tmux server now

$ tmux kill-server

Nope. Still not the expected behavior.

Update on Ubuntu

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Let’s check that my config does NOT work on the server.

$ git clone git@github.com:proullon/conf.git

First, nu crashes on startup. Let’s update it.

$ git clone git@github.com:nushell/nushell.git
$ git checkout 0.109.0
$ cargo build --release
$ cp target/release/nu /usr/local/bin/nu
$ nu --version

$ curl -s https://ohmyposh.dev/install.sh | bash -s -- -d ~/.local/bin

(yes, I know, that’s not ideal.)

$ cd /tmp
$ curl -LO https://github.com/neovim/neovim/releases/download/v0.11.5/nvim-linux-arm64.tar.gz
$ tar xzf nvim-linux-arm64.tar.gz
$ sudo mv nvim-linux-arm64 /opt/neovim
$ sudo ln -sf /opt/neovim/bin/nvim /usr/local/bin/nvim
$ cd /tmp
$ curl -LO https://github.com/tmux/tmux/releases/download/3.6/tmux-3.6.tar.gz
$ tar xzf tmux-3.6.tar.gz
$ cd tmux-3.6
$ ./configure
$ make
$ sudo make install
$ tmux -V
tmux 3.6

Let’s recap now:

tmux config debug

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So now I don’t have C-w in Neovim on both the desktop and the server. Yay. Also, C-l doesn’t clear the shell anymore. I now have to do C-w C-l.

So, to summarize:

To start, I’ll unbind C-w l last_window since I don’t use it.

unbind l

OK, time to debug. Let’s check why the test to detect whether the current pane is Vim isn’t working. Let’s add this shortcut to my config:

bind D run-shell '
cmd=$(ps -o comm= -p #{pane_pid})
tmux display-message "pane_pid=#{pane_pid} cmd=$cmd"
'

Surprise. In a Vim pane -> cmd: nu. In a pane with htop -> nu. OK.

Let’s try to display the child process

bind D run-shell '
children=$(ps --ppid #{pane_pid} -o comm= | tr "\n" " ")
tmux display-message "children=$children"
'

So, I guess, a correct is_vim would rather be:

is_vim='ps --ppid #{pane_pid} -o comm= | tr "\n" " " | grep -iq nvim'

Dumb forwarding

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ANYWAY. That’s not really the problem since is_vim is never evaluated anyway. Let’s change strategy. I’m going back to what I had in my config before:

bind-key 'h' 'send-keys C-w h'
bind-key 'j' 'send-keys C-w j'
bind-key 'k' 'send-keys C-w k'
bind-key 'l' 'send-keys C-w l'

I simply make tmux forward the entire sequence when it receives C-w h/j/k/l. Still no idea why it works at all on my laptop. That’s it. I’ll deal with being smart later. I’ll look at vim-tmux-navigator later: https://github.com/christoomey/vim-tmux-navigator.

vim-tmux-navigator

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OK. Let’s try to be smart and adapt.

I’ll add vim-tmux-navigator to my tmux config:

# tmux.conf
# (automatically handle C-h/j/k/l)
set -g @plugin 'christoomey/vim-tmux-navigator'

and to my Neovim config:

--- lua/plugins/tmux.conf
return {
    {
        "christoomey/vim-tmux-navigator",
        lazy = false,
        init = function()
            -- Disable default mappings if you want to control everything yourself
            -- Set to 1 ONLY if you want to define your own keymaps
            -- vim.g.tmux_navigator_no_mappings = 1
        end,
    },
}

I can now move around between nvim and tmux split seamlessly with C h/j/k/l.

It takes a month to cement a habit? Let’s see.