Keyboard issues with i3wm on Ubuntu 15.04
Since the update to 15.04 "Vivid Vervet" I've experienced some new input issues: I could not input some characters, most notably those requiring a combination of key to press. With a swiss-french layout I could not input stuff like ` ^ ~ and use my configured compose key. The culprit was unknown to me until then: IBus.
To solve this issue, you can either launch im-config(8) as user and select the "none" Input Method or simply do:
% echo "run_im none" > ~/.xinputrc