To get it up and running make sure you do:
apt-get install qt4-dev-tools apt-get install qt4-dev-tools
For copy and paste in xterm windows you can use the shortcuts CTRL-INS and SHIFT-INS. In alternative, you can select the text with the mouse, and use the third button of the mouse to paste it. On a laptop you can emulate the third button pressing the first and the second button together.
You can download Gerix here: gerix-wifi-cracker-master.zip