dual-GPU desktop setup: gnome-shell (3.28) segfault 5

Core was generated by `/usr/bin/gnome-shell'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  g_object_notify_queue_thaw (object=object@entry=0x7f78b806d6a0, nqueue=<optimized out>) at gobject.c:289
289	      pspecs[n_pspecs++] = slist->data;
[Current thread is 1 (Thread 0x7f78de598ac0 (LWP 3127))]
(gdb) bt
#0  0x00007f78dd99fa10 in g_object_notify_queue_thaw (object=object@entry=0x7f78b806d6a0 [GdkPixbuf], nqueue=<optimized out>) at gobject.c:289
#1  0x00007f78dd9a14e6 in g_object_new_internal (class=class@entry=0x7f78b8024470, params=params@entry=0x7ffe1593d400, n_params=n_params@entry=8) at gobject.c:1856
#2  0x00007f78dd9a314e in g_object_new_valist (object_type=<optimized out>, first_property_name=<optimized out>, var_args=var_args@entry=0x7ffe1593d550) at gobject.c:2122
#3  0x00007f78dd9a34c9 in g_object_new (object_type=<optimized out>, first_property_name=<optimized out>) at gobject.c:1642
#4  0x00007f78da8ae620 in gdk_pixbuf_new_from_data () at /usr/lib64/libgdk_pixbuf-2.0.so.0
#5  0x00007f78dcf67f96 in  () at /usr/lib64/libgtk-3.so.0
#6  0x00007f78db11a37c in on_symbolic_icon_loaded (source=0x3940400 [GtkIconInfo], result=0x423c6a0, user_data=0x449d070) at ../src/st/st-texture-cache.c:556
#7  0x00007f78ddc71063 in g_task_return_now (task=0x423c6a0 [GTask]) at gtask.c:1148
#8  0x00007f78ddc71099 in complete_in_idle_cb (task=0x423c6a0) at gtask.c:1162
#9  0x00007f78dd6c20e5 in g_main_dispatch (context=0x1448110) at gmain.c:3177
#10 0x00007f78dd6c20e5 in g_main_context_dispatch (context=context@entry=0x1448110) at gmain.c:3830
#11 0x00007f78dd6c24b0 in g_main_context_iterate (context=0x1448110, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3903
#12 0x00007f78dd6c27c2 in g_main_loop_run (loop=0x156fb30) at gmain.c:4099
#13 0x00007f78dbbd59ac in meta_run () at core/main.c:660
#14 0x00000000004022fc in main (argc=<optimized out>, argv=<optimized out>) at ../src/main.c:525
(gdb) print n_pspecs
$1 = 6
(gdb) print slist
$2 = 0x69772d6563616672 = {Cannot access memory at address 0x69772d6563616672