You will get a hard nasty crash if passing in a node into gui.get_spine_bone that actually isn’t a spine node.
Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0 dmengine 0x000000011056eee2 dmGui::GetNodeSpineBone(dmGui::Scene*, unsigned int, unsigned long long) + 178
1 dmengine 0x0000000110576d05 dmGui::LuaGetSpineBone(lua_State*) + 181
2 dmengine 0x000000011043f826 lj_BC_FUNCC + 52