Yarn: Problems installing packages globally

[metakermit]

Do you want to request a feature or report a bug?
Bug

What is the current behavior?

I am trying to install d3, but I'm getting a Cannot find module error.

If the current behavior is a bug, please provide the steps to reproduce.

$ yarn global add d3
yarn global v0.22.0
warning No license field
[1/4] 🔍  Resolving packages...
[2/4] 🚚  Fetching packages...
[3/4] 🔗  Linking dependencies...
[4/4] 📃  Building fresh packages...
warning undefined has no binaries
warning No license field
✨  Done in 2.00s.
$ node
> require('d3')
Error: Cannot find module 'd3'
    at Function.Module._resolveFilename (module.js:470:15)
    at Function.Module._load (module.js:418:25)
    at Module.require (module.js:498:17)
    at require (internal/module.js:20:19)
    at repl:1:1
    at ContextifyScript.Script.runInThisContext (vm.js:23:33)
    at REPLServer.defaultEval (repl.js:339:29)
    at bound (domain.js:280:14)
    at REPLServer.runBound [as eval] (domain.js:293:12)
    at REPLServer.onLine (repl.js:536:10)
>

Also, doing yarn global ls lists no packages.

$ yarn global ls
yarn global v0.22.0
warning No license field
✨  Done in 0.48s.

I installed yarn through homebrew. I tried reinstalling a few times, cleaning /usr/local/Cellar/node/7.8.0/bin and ~/.config/yarn/ beforehand. Nothing seems to help, though.

What is the expected behavior?

I would expect the globally installed module to be available.

Please mention your node.js, yarn and operating system version.

node - v7.8.0
yarn - 0.22.0
hometrew - 1.1.12
macOS - 10.12.2

[mrjamesriley]

This does appear to be a known issue, it's been affecting me too (Mac 10.12.4, Node 7.4.0, Yarn 0.22.0). This thread has a solution that works for me: https://github.com/yarnpkg/yarn/issues/2790

That being, to add the following directory to my PATH:
$HOME/.config/yarn/global/node_modules/.bin
(as the globally installed packages are hiding out there, a location not in your path by default)

[metakermit]

I don't expect this to be connected to my PATH variable as I'm not trying to use d3 as an executable. I'm trying to require it as a module.

[jddxf]

I don't think it is a good idea to require global modules as they are mostly used as a cli tool.Though, if you really want to, you can expose the global module directory to NODE_PATH env variable so that Node.js knows where to find the module (details).In your case, it is ~/.config/yarn/global/node_modules.

[metakermit]

@jddxf ok, I understand. Yeah, I ended up solving the issue for myself by locally installing the d3 module. Just thought it might be good to report it, since I found the behaviour unexpected. Is this something that should be noted in the docs for the yarn global command?

[jddxf]

If you expect the globally installed module to be available I would say Yarn has already done that. Even if you're using npm, you'll need to do the same thing to properly require a global module.

[sivabudh]

Real problem. Not sure what the problem is, so I just use npm install global Lol.

[maxlk]

@jddxf The problem is that globally installed modules are not available in REPL by default.
I know 2 valid (not considered as bad practices) use cases of using global modules:

• CLI
• REPL

The first is covered by yarn global while the second isn't.

To clarify: I understand that manually modifying NODE_PATH allows using yarn's global modules in REPL. The issue is that yarn is expected to do it by itself by default.

[ayuthmang]

Guys, I've found the solutions.

If you really want to install the module globally and require them in node command then you should set NODE_PATH by add the following line on your ~/.zshrc or ~/.bash_profile.

If you are using yarn

$ export NODE_PATH=$(yarn global dir)/node_modules
# or node
$ export NODE_PATH=$(npm root --quiet -g)

Then try to reload the bash session and require again.
That works on my mac.

Refs:
https://stackoverflow.com/questions/7970793/how-do-i-import-global-modules-in-node-i-get-error-cannot-find-module-module