yarn global add package does not update packages to a newer version

[thibmaek]

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

Bug
What is the current behavior?
Running yarn global add now does not update the globally installed package
If the current behavior is a bug, please provide the steps to reproduce.
Install an older version of a package (eg. now) globally and try to update it with yarn global add <pkg>
What is the expected behavior?
It updates the package to the latest version
Please mention your node.js, yarn and operating system version.
v7.0.0, 0.16.1, macOS Sierra 10.12.1

Screenshot: https://www.dropbox.com/s/iadtz3psodr972h/Screenshot%202016-11-13%2018.19.57.png?dl=0

[wyze]

Duplicate #1321. Seems it installs successful, but not in the correct path.