The screenshot I posted came from PCBNew in KiCAD release (2017-02-10 revision 1BCBBB4). I couldn't find any way to make the "hollow lines" in Footprint Editor.
Do you get the same result in both Legacy Canvas and OpenGL? It's grasping at straws, but can you try a different graphics driver?
If it's a bug in the nightly builds then it definitely needs to be reported. (They should be getting close to a major release.) But I'd be reluctant to submit a squawk unless somebody can confirm the problem.