Missing global dependency generates unhelpful message

[BurtHarris]

Do you want to request a feature or report a bug?
Bug - Unhelpful error message

What is the current behavior?

Commands like yarn global list are failing on my system with the message error "C:\\code\\antlr4ts\\tool" doesn't exist. This is of my own doing (I recognize the missing directory, and had intentionally deleted it) but it wasn't clear how to recover. More context on what yarn was doing would have helped.

I tracked it down to the file C:\Users\Burt_\AppData\Local\Yarn\config\global\package.json, which contained:

{
  "dependencies": {
    "antlr4ts-cli": "file:\\code\\antlr4ts\\tool",
    "gulp-cli": "^2.0.0",
    "lerna": "^2.5.1",
    "rimraf": "^2.6.2",
    "typescript": "^2.6.2"
  }
}

Workaround

Once I knew what package was involved, yarn global remove antlr4ts-cli fixed it up.

Stack Trace

verbose 0.669 Error: "C:\\code\\antlr4ts\\tool" doesn't exist.
    at MessageError (C:\Program Files (x86)\Yarn\lib\cli.js:139:5)
    at C:\Program Files (x86)\Yarn\lib\cli.js:48701:15
    at next (native)
    at step (C:\Program Files (x86)\Yarn\lib\cli.js:92:30)
    at C:\Program Files (x86)\Yarn\lib\cli.js:103:13

If the current behavior is a bug, please provide the steps to reproduce.
Sorry, I wish I could answer better how I got this entry. As a guess, I must have used something like:

yarn global add file:c:\\code\antlr4ts\tool

What is the expected behavior?
Best would be to recover automatically from this using behavior like yarn global remove

Please mention your node.js, yarn and operating system version.
os: Microsoft Windows [Version 10.0.16299.125]
node: v6.12.2
yarn: 1.3.2 (installed w/ .msi)

[rally25rs]

It seems reasonable that on error, we could have a message that says something like The ___ package appears to be missing. It may have been deleted. You can remove this from Yarn's like of global packages with the command "yarn global remove ___"

Or someone propose better wording...

[iansu]

This seems to be unique to file:// URLs where the file pointed to is missing. This can happen with local and global packages so that makes the error message a bit trickier. Maybe just something like <dir> doesn't exist. It may have been deleted. You can remove it with the command "yarn remove <package name>"?

[BurtHarris]

Either message would have made things easier...