ios - Ignore sibling order in Scene Kit overlaySKScene -

i using overlayskscene in scene kit. in skscene, using mask node crop skcropnode. mask node works when run on mac os x, when run on ios doesn't work.

i think that's because ios ignoring sibling order , mask node shows behind skcropnode. when try set

view.ignoresiblingorder = no; 

in skscene, crashes , says:

[gameview setignoressiblingorder:]: unrecognized selector sent instance 

gameview subclass of scnview, understand scnview doesn't have property "ignoresiblingorder".

how solve this? approaching wrong way? bug in scene kit when run on ios?