turn off ant build notify-send / growl notifications

On Centos 6.5 when I execute ant from hybris 5.1.1 such as ant build, it creates a notify-send window with the message "Build has started", and subsequently "Build has finished" when the build is complete.

How do I turn that off? It is creating a notification for every single extension when I build in Ee, and it is getting in the way. I'd rather not have the notification at all.