Running on F25, I installed cura. (15.04.4-5.fc25)
(I have tried slic3r and haven't figured out how to tune it to get usable gcode.)
(And I can't figure out skeinforge.)

On cura, the button the docs tell me is the 'save' button' doesn't have an icon
and isn't clickable. And the 'Save Gcode' menu item doesn't appear to do anything either.

What am I missing ?