Comment 6 for bug 664273

So the problem never was resolved, but I was able to bypass simply executing "unity --reset"

Then couple of weeks ago that method become useless, but moving to gdm3 was a workaround.

Early today I've updated to 18.04 and the problem started to appear on there as well.

So I decided to debug a bit and finally was able to find that killing `ibus-ui-gtk3` made the spacebar work normally.

For now I've removed such package (ibus-gtk3) as I dont need multiple language entry support