Daniel Bull, who created the excellent CamJam EduKit 3 3D printed chassis, wanted to set-up wifi on his Pi Zero. He downloaded Raspbian Jessie Lite (the cut-down version of Raspbian now offered by the Raspberry Pi Foundation) but found that WICD, his usual method of setting up wifi in a command-line environment, didn’t work. After 3 hours of messing around, he discovered that it conflicted with dhcpcd5. Removing this made WICD work again. He has posted about it on G+ but here are the instructions anyway:
To install WICD:
sudo apt-get install wicd-curses
To remove dhcpcd5:
sudo apt-get remove dhcpcd5
Once you’ve done those two commands, WICD will be up and running again.