if someone calls size_hint_min_set(box, -1, -1) to force a recalc on a box, the box will fail to re-set its size hints on the elm widget object if the inner box's size hints have not changed.
elm_box 10x10 [ evas_box 10x10 ]
size_hint_min_set(elm_box, -1, -1)
elm_box -1x-1 [ evas_box 10x10 ]
the elm_box _sizing_eval() function can only be called if the size hints of the inner evas box have changed