Comment 2 for bug 1766938

apport-retrace -g _usr_bin_gnome-shell.1000.crash

bt

indicates it's an assert in standard_pict_format_for_depth:

(gdb) bt
#0 0x00007f75c68f0727 in raise (sig=<optimized out>) at ../sysdeps/unix/sysv/linux/raise.c:51
#1 0x000056149221ba6b in dump_gjs_stack_on_signal_handler (signo=6) at ../src/main.c:367
#2 0x00007f75c68f0890 in <signal handler called> () at /lib/x86_64-linux-gnu/libpthread.so.0
#3 0x00007f75c652be97 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51
#4 0x00007f75c652d801 in __GI_abort () at abort.c:79
#5 0x00007f75c868dfa5 in g_assertion_message () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#6 0x00007f75c868e00a in g_assertion_message_expr () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#7 0x00007f75c6bb5fbe in standard_pict_format_for_depth (depth=<optimized out>) at x11/iconcache.c:303
#8 0x00007f75c6bb5fbe in pict_format_for_depth (depth=<optimized out>, xdisplay=0x56149472f000) at x11/iconcache.c:310
#9 0x00007f75c6bb5fbe in surface_from_pixmap (xdisplay=xdisplay@entry=0x56149472f000, xpixmap=xpixmap@entry=31457330, height=<optimized out>, width=<optimized out>)
    at x11/iconcache.c:325
#10 0x00007f75c6bb6117 in try_pixmap_and_mask (display=0x5614949c0200, src_pixmap=src_pixmap@entry=31457330, src_mask=src_mask@entry=31457332, iconp=iconp@entry=0x7fff9d183198) at x11/iconcache.c:345
#11 0x00007f75c6bb65a4 in meta_read_icons (screen=0x56149454bcd0, xwindow=31457316, icon_cache=0x561495d18df8, wm_hints_pixmap=31457330, wm_hints_mask=31457332, iconp=iconp@entry=0x7fff9d183198, ideal_width=96, ideal_height=96, mini_iconp=0x7fff9d1831a0, ideal_mini_width=16, ideal_mini_height=16) at x11/iconcache.c:546
#12 0x00007f75c6bbd3c1 in meta_window_x11_update_icon (window=0x561495d18e30, icon=0x7fff9d183198, mini_icon=0x7fff9d1831a0) at x11/window-x11.c:1472
#13 0x00007f75c6ba2608 in meta_window_update_icon_now (window=window@entry=0x561495d18e30, force=force@entry=1) at core/window.c:5326
#14 0x00007f75c6ba9abd in _meta_window_shared_new (display=display@entry=0x5614949c0200, screen=screen@entry=0x56149454bcd0, client_type=client_type@entry=META_WINDOW_CLIENT_TYPE_X11, surface=surface@entry=0x0, xwindow=xwindow@entry=31457316, existing_wm_state=existing_wm_state@entry=0, effect=<optimized out>, attrs=<optimized out>)
    at core/window.c:1148
#15 0x00007f75c6bbf6a0 in meta_window_x11_new (display=display@entry=0x5614949c0200, xwindow=31457316, must_be_viewable=must_be_viewable@entry=0, effect=effect@entry=META_COMP_EFFECT_CREATE) at x11/window-x11.c:3148
#16 0x00007f75c6bb4554 in handle_other_xevent (display=display@entry=0x5614949c0200, event=event@entry=0x7fff9d183640) at x11/events.c:1372
#17 0x00007f75c6bb4deb in meta_display_handle_xevent (event=0x7fff9d183640, display=0x5614949c0200) at x11/events.c:1791
#18 0x00007f75c6bb4deb in xevent_filter (xevent=0x7fff9d183640, event=<optimized out>, data=0x5614949c0200) at x11/events.c:1830
#19 0x00007f75c5e07edf in () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#20 0x00007f75c5e081c9 in () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#21 0x00007f75c5dd2d70 in gdk_display_get_event () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#22 0x00007f75c5e07f72 in () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#23 0x00007f75c8667287 in g_main_context_dispatch () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#24 0x00007f75c86674c0 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#25 0x00007f75c86677d2 in g_main_loop_run () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#26 0x00007f75c6b94a7c in meta_run () at core/main.c:664