Flex example not displaying correctly

[WhoAteDaCake]

I am not sure whether this is a platform specific thing, but when running on ubuntu Flexbox example displays:

Unless I am missunderstanding the examples, should the text Flex end be at the end of the row?

[tcoopman]

Does this still happen, on Archlinux it works correctly on master.

Although, now that I'm looking at the image, I'm wondering if Flex Stretch shouldn't take full width?