[Bug] Unable to upgrade the CLI to 3.12.0

Hi,
When i created a new build for my project, it asked me to upgrade to 3.12.0. But, when i pressed Y, it gave an error and deleted ionic as well.
So, i reinstalled ionic and it installed to the latest version. Though it works now, thought it might be a bug that needs to be fixed.

 ? The Ionic CLI has an update available (3.10.3 => 3.12.0)! Would you like to i
> npm install -g ionic@latest
× Running command - failed!
Error
    at ShellException.Exception (C:\Users\sd0003\AppData\Roaming\npm\node_modules\ionic\node_modules\@ionic\cli-utils\lib\errors.js:8:23)
    at ShellException (C:\Users\sd0003\AppData\Roaming\npm\node_modules\ionic\node_modules\@ionic\cli-utils\lib\errors.js:26:9)
    at ChildProcess.p.on (C:\Users\sd0003\AppData\Roaming\npm\node_modules\ionic\node_modules\@ionic\cli-utils\lib\utils\shell.js:66:28)
    at emitTwo (events.js:106:13)
    at ChildProcess.emit (events.js:191:7)
    at ChildProcess.cp.emit (C:\Users\sd0003\AppData\Roaming\npm\node_modules\ionic\node_modules\cross-spawn\lib\enoent.js:40:29)
    at maybeClose (internal/child_process.js:920:16)
    at Socket.<anonymous> (internal/child_process.js:351:11)
    at emitOne (events.js:96:13)
    at Socket.emit (events.js:188:7)

Please report this as a bug at https://github.com/ionic-team/ionic-cli/issues