freyja-dev/unity-tweak-tool — pull request #124 by phanimahesh (2013-11-27 06:45:49+00:00)
Title: Set DISPLAY to prevent DBUS crash. (LP:#1233004)

https://errors.ubuntu.com/problem/5ce3e25dca09d233db038f04e57e179dda28ec9b

Problem declined with time, suggesting upstream fix, but to be on the safe side, let's do it anyway.