font bug screenshot

This weird font bug (notice the grey dots next to the upper prompt) has been around for some months now. I couldn’t reproduce it in xterm, I’ve been seeing it in gnome-terminal for a long time now. I’ve only seen it with single bold

and < chars in the DejaVu and Vera fonts so far. Maybe these characters are too wide, and the antialiasing wraps back into the character cell?

Focusing sometimes makes the bug disappear, sometimes not. Even (as in the screenshot) sometimes only for some of the prompts on the screen.