(gdb) bt
#0  _cogl_material_layer_get_authority (layer=0x0, difference=2)
    at ./cogl-material.c:587
#1  0x00007ffff72c82bb in _cogl_material_layer_pre_paint (layer=0x0)
    at ./cogl-material.c:5198
#2  0x00007ffff72bd997 in _cogl_rectangles_with_multitexture_coords (
    rects=0x7fffffff96b0, n_rects=1) at ./cogl-primitives.c:566
#3  0x00007ffff72bdc9b in cogl_rectangle_with_multitexture_coords (
    x_1=<value optimized out>, y_1=<value optimized out>, 
    x_2=<value optimized out>, y_2=<value optimized out>, 
    user_tex_coords=<value optimized out>, 
    user_tex_coords_len=<value optimized out>) at ./cogl-primitives.c:800
#4  0x00007fffed95e0f1 in st_theme_node_transition_paint (
    transition=<value optimized out>, allocation=0x7fffffff9790, 
    paint_opacity=43 '+') at st/st-theme-node-transition.c:330
#5  0x00007fffed9621a4 in st_widget_paint (actor=0x2adbad0)
    at st/st-widget.c:380
#6  0x00007fffed93d29a in st_bin_paint (self=0x2adbad0) at st/st-bin.c:116
#7  0x00007ffff58982e9 in g_closure_invoke (closure=0xa731f0, 
    return_value=0x0, n_param_values=1, param_values=0x2b43680, 
    invocation_hint=0x7fffffff9930) at gclosure.c:766
#8  0x00007ffff58b05b2 in signal_emit_unlocked_R (node=<value optimized out>, 
    detail=0, instance=0x2adbad0, emission_return=0x0, 
    instance_and_params=0x2b43680) at gsignal.c:3290
#9  0x00007ffff58b20d6 in g_signal_emit_valist (
    instance=<value optimized out>, signal_id=<value optimized out>, 
    detail=<value optimized out>, var_args=0x7fffffff9b20) at gsignal.c:2983
#10 0x00007ffff58b2903 in g_signal_emit (instance=<value optimized out>, 
    signal_id=<value optimized out>, detail=<value optimized out>)
    at gsignal.c:3040
#11 0x00007ffff723b89e in clutter_actor_paint (self=0x2adbad0)
    at ./clutter-actor.c:2479
#12 0x00007fffed930098 in shell_generic_container_paint (actor=0xe08760)
    at shell-generic-container.c:140
