Hi , Below is easy tut about how to install last Ettercap on Kali .

first install all Dependency :

Code:
apt-get install python-gtk2-dev libnet1-dev cmake flex libpcap0.8-dev libncurses5-dev
now download ettercap with git .

Code:
git clone https://github.com/Ettercap/ettercap.git
now cmake it with cmake <ettercap folder path> ( cmake ~/Desktop/ettercap )

it shoud cmake it without error , and now make after make end now make install

i hope worked for all .