Since the retracer ate the backtrace, here's a new one.

#0  0x00007ffff51ff475 in __GI_raise (sig=<optimized out>)
    at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#1  0x00007ffff5202bdb in __GI_abort () at abort.c:91
#2  0x00007ffff523b0ee in __libc_message (do_abort=2, 
    fmt=0x7ffff5343270 "*** glibc detected *** %s: %s: 0x%s ***\n")
    at ../sysdeps/unix/sysv/linux/libc_fatal.c:201
#3  0x00007ffff52458e6 in malloc_printerr (action=3, 
    str=0x7ffff5340221 "free(): invalid pointer", ptr=<optimized out>)
    at malloc.c:5007
#4  0x00007ffff57d7b10 in g_datalist_clear (datalist=0x0)
    at /build/buildd/glib2.0-2.31.16/./glib/gdataset.c:283
#5  0x00007ffff5cd2f3d in g_object_finalize (object=0xb20170)
    at /build/buildd/glib2.0-2.31.16/./gobject/gobject.c:1008
#6  0x00007ffff5cd2b93 in g_object_unref (_object=0xb20170)
    at /build/buildd/glib2.0-2.31.16/./gobject/gobject.c:3008
#7  0x00007ffff728929d in gtk_menu_shell_forall (container=<optimized out>, 
    include_internals=<optimized out>, 
    callback=0x7ffff73ab310 <gtk_widget_destroy>, callback_data=0x0)
    at /build/buildd/gtk+3.0-3.3.14/./gtk/gtkmenushell.c:1223
#8  0x00007ffff71dc9b7 in gtk_container_destroy (widget=0x6a76b0)
    at /build/buildd/gtk+3.0-3.3.14/./gtk/gtkcontainer.c:1390
#9  0x00007ffff5ccf2da in g_closure_invoke (closure=0x669440, 
    return_value=0x0, n_param_values=1, param_values=0x8bfa80, 
    invocation_hint=<optimized out>)
    at /build/buildd/glib2.0-2.31.16/./gobject/gclosure.c:774
#10 0x00007ffff5cdf4f7 in signal_emit_unlocked_R (node=<optimized out>, 
    detail=0, instance=<optimized out>, emission_return=0x0, 
    instance_and_params=0x8bfa80)
    at /build/buildd/glib2.0-2.31.16/./gobject/gsignal.c:3418
#11 0x00007ffff5ce700b in g_signal_emit_valist (instance=<optimized out>, 
    signal_id=<optimized out>, detail=<optimized out>, var_args=0x7fffffffd868)
    at /build/buildd/glib2.0-2.31.16/./gobject/gsignal.c:3033
#12 0x00007ffff5ce71d2 in g_signal_emit (instance=<optimized out>, 
    signal_id=<optimized out>, detail=<optimized out>)
    at /build/buildd/glib2.0-2.31.16/./gobject/gsignal.c:3090
#13 0x00007ffff73b66ea in gtk_widget_dispose (object=0x6a76b0)
    at /build/buildd/gtk+3.0-3.3.14/./gtk/gtkwidget.c:10112
#14 0x00007ffff5cd3f60 in g_object_run_dispose (object=0x6a76b0)
    at /build/buildd/glib2.0-2.31.16/./gobject/gobject.c:1051
#15 0x00007ffff7285da5 in gtk_menu_item_destroy (widget=0xa76980)
    at /build/buildd/gtk+3.0-3.3.14/./gtk/gtkmenuitem.c:679
#16 0x00007ffff5ccf384 in g_closure_invoke (closure=0x669440, 
    return_value=0x0, n_param_values=1, param_values=0x8bea60, 
    invocation_hint=<optimized out>)
    at /build/buildd/glib2.0-2.31.16/./gobject/gclosure.c:774
#17 0x00007ffff5cdf4f7 in signal_emit_unlocked_R (node=<optimized out>, 
    detail=0, instance=<optimized out>, emission_return=0x0, 
    instance_and_params=0x8bea60)
    at /build/buildd/glib2.0-2.31.16/./gobject/gsignal.c:3418
#18 0x00007ffff5ce700b in g_signal_emit_valist (instance=<optimized out>, 
    signal_id=<optimized out>, detail=<optimized out>, var_args=0x7fffffffdca8)
    at /build/buildd/glib2.0-2.31.16/./gobject/gsignal.c:3033
#19 0x00007ffff5ce71d2 in g_signal_emit (instance=<optimized out>, 
    signal_id=<optimized out>, detail=<optimized out>)
    at /build/buildd/glib2.0-2.31.16/./gobject/gsignal.c:3090
#20 0x00007ffff73b66ea in gtk_widget_dispose (object=0xa76980)
    at /build/buildd/gtk+3.0-3.3.14/./gtk/gtkwidget.c:10112
#21 0x00007ffff5cd3f60 in g_object_run_dispose (object=0xa76980)
    at /build/buildd/glib2.0-2.31.16/./gobject/gobject.c:1051
#22 0x00007ffff580cc97 in g_slist_foreach (list=<optimized out>, 
    func=0x412a80 <gtk_widget_destroy@plt>, user_data=0x0)
    at /build/buildd/glib2.0-2.31.16/./glib/gslist.c:840
#23 0x00007ffff580ccbb in g_slist_free_full (list=0x990c60, 
    free_func=<optimized out>)
    at /build/buildd/glib2.0-2.31.16/./glib/gslist.c:177
#24 0x0000000000427867 in wireless_add_menu_item (device=0x6a12e0, 
    n_devices=<optimized out>, active=<optimized out>, menu=0x6a72b0, 
    applet=0x0) at applet-device-wifi.c:1107