virt-manager xforward to OSX (release mouse)

When you forward virt-manager from a linux machine to OS X and try to release the mouse from the console, you might have noticed that this won’t work.

If you use XQuartz, simply go into preferences, select “Option keys send Alt_L and Alt_R”.

Source: https://major.io/2013/03/20/virt-manager-wont-release-the-mouse-when-using-ssh-forwarding-from-os-x/