Sometimes I echo a string to the standard output (I see it at the Kubuntu console) and a trailing % symbol gets appended with it's colors inverted (black text on white background).
I can't find any accidental additional character (or half-baked-UTF8 or anything) in the string I'm printing. The character seems to get added when the program finishes.
I'm using Go (golang) right now, but I've already seen this in the past, and I think I was using PHP back then.
What could be causing this?