[BUG with Solution] `:MarkdownPreview` prints `Node.js v22.6.0` and does nothing

[iamhrigved]

Describe the bug

I installed this plugin with the following setup

{
    "iamcco/markdown-preview.nvim",
    cmd = { "MarkdownPreviewToggle", "MarkdownPreview", "MarkdownPreviewStop" },
    ft = { "markdown" },
    build = function() vim.fn["mkdp#util#install"]() end,
}

When I tried to run :MarkdownPreview it just printed Node.js v22.6.0 and did nothing.

To Reproduce

Steps to reproduce the behavior:

1. Add the plugin with lazy
2. Open a markdown file
3. Do :MarkdownPreview

Expected behavior

A browser window should open with the preview of the markdown file.

Desktop

• OS: Arch Linux
• WM: Hyprland
• Browser: Brave Browser

Solution

I saw this issue and tried the following:

cd ~/.local/share/nvim/lazy/markdown-preview.nvim
npm install

I then tried to do MarkdownPreview and it worked !!!

[crolbar]

maybe a better solution would be to do something like this:

build = "npm install",

or

build = "cd app && yarn install",

[stevenwalton]

This initially provided a fix and then I started getting Pre build and node is not found.

I use Plug and I tried via the commands listed in the README as well as issuing manually. I tried deleting and reinstalling. This seems to sometimes work and sometimes fail (after initially working). Output always looked like this regardless of working or failing

$ rm -r ~/.vim/plugged/markdown-preview.nvim
$ vim -c "PlugInstall" -c "qa"
yarn install v1.22.22
[1/4] 🔍  Resolving packages...
[2/4] 🚚  Fetching packages...
[3/4] 🔗  Linking dependencies...
[4/4] 🔨  Building fresh packages...
✨  Done in 0.26s.
$ vim ~/.dotfiles/README.md -c "MarkdownPreview"

So if other users are experiencing this, I'm not sure what to say but maybe try a few times. There's clearly something else afoot but might need more reports to find the right cause.

This was done on a M2 Mac Air

[stevenwalton]

FWIW I upgraded to Sequoia and this broke again. Tried a full reinstall and nothing. yarn's output looks exactly like before.

[Opposite34]

I haven't tried this (my system needed the npx workaround at #690 so I couldn't try it), but the line after vim.fn["mkdp#util#install"]() try add this: vim.cmd("!cd " .. plugin.dir .. " && npm install") so it'd be:

build = function() 
    vim.fn["mkdp#util#install"]()
    vim.cmd("!cd " .. plugin.dir .. " && npm install")
    end,

Speaking of #690 , if you're using that workaround with npx, try this for the build command. This one I've tested to be working for my system:

    build = function(plugin)
        if vim.fn.executable "npx" then
            vim.cmd("!cd " .. plugin.dir .. " && cd app && npx --yes yarn install && npm install")
        else
            vim.cmd [[Lazy load markdown-preview.nvim]]
            vim.fn["mkdp#util#install"]()
        end
    end,

(essentially vim.cmd("!cd " .. plugin.dir .. " && cd app && npx --yes yarn install && npm install") also has npm install at the end now)

[bryan-melanson]

I just worked through this - NodeJS is throwing an error and you're just seeing the notification for it.

Try running :messages to view more detail and install what is likely some missing modules.

[nyngwang]

If you're using folke/lazy.nvim, it seems that we have to use a ':call cmd_string' to make it work for this plugin:

build = ':call mkdp#util#install()'

Instead of the function (), i.e. the following do NOT work:

build = function() vim.fn['mkdp#util#install']() end

[TheAnsIs42]

@nyngwang This works! I used to npm install in the plugin's app directory. But that will make upgrade in lazy always warning. This approach fixes it!

[ajiankexx]

@iamhrigved Thank your for your method! I meet the same question with Node.js v20.13.0 instead. I have been puzzled by this bug for a long time, your advice sucessfully address my problem!

[nickjj]

I am getting this issue now too with LazyVim but it wasn't always a problem.

I can't say when exactly the problem occurred but I had this config for like 6 months and it was ok:

  {
    "iamcco/markdown-preview.nvim",
    build = "cd app && yarn install",
  },

I've been keeping my packags up to date. Today I noticed that when I run the preview command, the browser doesn't open and I see the Node version printed. If I add cmd = { "MarkdownPreviewToggle", "MarkdownPreview", "MarkdownPreviewStop" } (this wasn't needed before) the same problem happens. The commands are available, they just don't launch the browser.

I am using WSL 2 with Node v22.14.0. I am not getting the same problem on macOS with the same Node version and same dotfiles.

[nickjj]

I don't know what changed but WSL 2 no longer was able to open Windows apps. For example running explorer.exe . failed and instead threw an exec format error. I restarted WSL 2 and everything worked again, including :MarkdownPreview. I can't say for sure what it was tho because I changed nothing on the Neovim side of things.

Maybe a takeaway here is if it prints the Node version, that is really masking any arbitrary error?

[Mo0rBy]

I also bumped into this.

Here is the stacktrace I see with :messages (thought it might be useful for @iamcco to see):

node:internal/modules/cjs/loader:1408
  throw err;
  ^
Error: Cannot find module 'tslib'
Require stack:
- /Users/mo0rby/.local/share/nvim/lazy/markdown-preview.nvim/app/lib/app/index.js
- /Users/mo0rby/.local/share/nvim/lazy/markdown-preview.nvim/app/index.js
    at Module._resolveFilename (node:internal/modules/cjs/loader:1405:15)
    at defaultResolveImpl (node:internal/modules/cjs/loader:1061:19)
    at resolveForCJSWithHooks (node:internal/modules/cjs/loader:1066:22)
    at Module._load (node:internal/modules/cjs/loader:1215:37)
    at TracingChannel.traceSync (node:diagnostics_channel:322:14)
    at wrapModuleLoad (node:internal/modules/cjs/loader:235:24)
    at Module.require (node:internal/modules/cjs/loader:1491:12)
    at require (node:internal/modules/helpers:135:16)
    at Object.<anonymous> (/Users/mo0rby/.local/share/nvim/lazy/markdown-preview.nvim/app/lib/app/index.js:3:17)
    at Module._compile (node:internal/modules/cjs/loader:1734:14) {
  code: 'MODULE_NOT_FOUND',
  requireStack: [
    '/Users/mo0rby/.local/share/nvim/lazy/markdown-preview.nvim/app/lib/app/index.js',
    '/Users/mo0rby/.local/share/nvim/lazy/markdown-preview.nvim/app/index.js'
  ]
}
Node.js v24.2.0

I tried a few of the suggestions in this thread to update the build = <something> section on my plugin config (as that is how I would have preferred to fix it) but I couldn't get any working.

The thing that worked for me was doing what @iamhrigved initially suggested and doing the following:

cd ~/.local/share/nvim/lazy/markdown-preview.nvim
npm install