The current solution is not the best solution, and it should not break existing code. The background is the use of FLUID and other tools in the command line. Depending on the OS, opening a connection to the display may throw an error if the tool is intended for the command line. So we try to leave all measuring of fonts and other machine relevant data until the app calls `show()`. This works generally very well, because font size commonly don't need to be known until a widget is shown or drawn. But as we see here, this is not always the case and can not always be expected from the user.

I hope we find a solution to that soon. Probably just calling fl_open_display() whenever the graphics driver is requested, but not yet initialised, ie enough. Other core devs?

    I think the OP's problem (which he's since corrected) is probably one of assuming
    a font had already been set, as I *think* what he's saying is he called the getter
    version of fl_font(), e.g. "fl_font(void)", without having first called fl_font(face,size) to set it,
    which probably would have yielded "undefined behavior".

    Anyway, he's since fixed the problem.

    It's certainly a valid use (and documented) to call fl_font() outside of draw(),
    such as to measure text with fl_measure() during widget construction, before graphics
    has been initialized. I'm guessing fl_font(face,size) checks if graphics has not yet been
    initialized, and initializes it.. but fl_font(void) does not (and perhaps shouldn't)