mason.nvim update tools from command line

[jessefarinacci]

Thank you for Mason! :) It's truly valuable and makes working in Neovim even more of a pleasure.

I would like to update all Mason-installed tools externally to an open nvim editor. I currently do this for all my lazy.nvim-installed plugins via nvim --headless '+Lazy! sync' +qa which works nicely from my shell/crontab. When I try to do a similar update for Mason it fails nvim --headless '+MasonUpdate!' +qa:

❯ nvim --headless '+MasonUpdate!' +qa
Error in command line:
E492: Not an editor command: MasonUpdate!

My environment:

❯ nvim --version
NVIM v0.12.5
Build type: Release
LuaJIT 2.1.1788856981

neovim > lazy > mason.nvim:
mason.nvim 13.45ms  VeryLazy
        dir     /Users/jlf/.local/share/nvim/lazy/mason.nvim
        url     https://github.com/mason-org/mason.nvim
        version 2.3.1
        tag     v2.3.1
        branch  main
        commit  2a6940a
        readme  README.md
        help    |mason.nvim|
        keys     <leader>cm 
        event    VeryLazy 
        cmd      Mason 

I'm not a Neovim expert by any stretch, am I doing something obviously wrong? Any help to get this working would be tremendously appreciated!

Thanks again for Mason! :)

[XNinety9]

Two things are going on here:

1. With lazy.nvim, mason is lazy-loaded in your setup (VeryLazy/cmd), and in headless mode VeryLazy never fires, so the :Mason* commands don't exist yet. You can load it explicitly with +Lazy! load mason.nvim first.
2. Even once it's loaded, :MasonUpdate only updates the registry (the list of available versions), not the installed tools. It doesn't take a ! either.

There's no built-in "upgrade everything" command, but the registry API makes it a one-liner. This refreshes the registry, then reinstalls only the packages whose installed version differs from the latest:

nvim --headless '+Lazy! load mason.nvim' '+MasonUpdate' \
  '+lua local names = {} for _, p in ipairs(require("mason-registry").get_installed_packages()) do if p:get_installed_version() ~= p:get_latest_version() then table.insert(names, p.name) end end if #names > 0 then vim.cmd("MasonInstall " .. table.concat(names, " ")) end' \
  +qa

:MasonInstall blocks until the installs are done when running headless, so it's safe to use from cron. I tested it with the same versions as you (Neovim 0.12.5, mason.nvim 2.3.1, lazy-loaded the same way): shfmt went from 3.7.0 to 3.14.1, and stylua, which was already up to date, was left alone.

[jessefarinacci]

@XNinety9 you're amazing, thank you so much :-)

[XNinety9]

Ahah glad to help! Don't forget to accept the answer 😉