(05:11:57 PM) [GBC]spreng: hi #zk
(05:12:09 PM) [GBC]spreng: i want to use the cool alt-build feature, the "insert in front of queue"
(05:12:30 PM) [GBC]spreng: but i'm using spring in fullscreen-window mode on ubuntu, and alt is intercepted by X for window-drag
(05:12:39 PM) [GBC]spreng: can i change the binding to use anything except alt?
(05:16:11 PM) KingRaptor: I suspect not
(05:16:18 PM) KingRaptor: might want to bring it up on engine forums

You can use /grabinput. I use it for the exact same reason.