[Console output]
fmt: png, ['image/png']
Hello again - button 1 was pressed
fmt: �q�, ['image/png']
Hello again - button 1 was pressed
[Here I pressed button 2]
[begin backtrace]
Program received signal SIGSEGV, Segmentation fault.
__strcmp_sse42 () at ../sysdeps/x86_64/multiarch/strcmp.S:260
260 ../sysdeps/x86_64/multiarch/strcmp.S: No such file or directory.
(gdb) set height 0
(gdb) bt
#0  __strcmp_sse42 () at ../sysdeps/x86_64/multiarch/strcmp.S:260
#1  0x00007ffff4fd78a4 in cache_alias_lookup (
    alias=0x55f <Address 0x55f out of bounds>)
    at /tmp/buildd/glib2.0-2.30.2/./gio/xdgmime/xdgmimecache.c:338
#2  __gio_xdg_cache_unalias_mime_type (
    mime=0x55f <Address 0x55f out of bounds>)
    at /tmp/buildd/glib2.0-2.30.2/./gio/xdgmime/xdgmimecache.c:929
#3  0x00007ffff4f29970 in g_content_type_from_mime_type (
    mime_type=0x55f <Address 0x55f out of bounds>)
    at /tmp/buildd/glib2.0-2.30.2/./gio/gcontenttype.c:867
#4  0x00007ffff2050bf7 in ?? ()
   from /usr/lib/x86_64-linux-gnu/libgdk_pixbuf-2.0.so.0
#5  0x00007ffff2052e5c in ?? ()
   from /usr/lib/x86_64-linux-gnu/libgdk_pixbuf-2.0.so.0
#6  0x00007ffff2053d5b in gdk_pixbuf_loader_write ()
   from /usr/lib/x86_64-linux-gnu/libgdk_pixbuf-2.0.so.0
#7  0x00007ffff2051869 in gdk_pixbuf_get_file_info ()
   from /usr/lib/x86_64-linux-gnu/libgdk_pixbuf-2.0.so.0
#8  0x00007ffff5b4a7bc in ffi_call_unix64 ()
   from /usr/lib/x86_64-linux-gnu/libffi.so.5
#9  0x00007ffff5b4a237 in ffi_call ()
   from /usr/lib/x86_64-linux-gnu/libffi.so.5
#10 0x00007ffff61abbc0 in ?? () from /usr/lib/libgirepository-1.0.so.1
#11 0x00007ffff61acf2e in g_function_info_invoke ()
   from /usr/lib/libgirepository-1.0.so.1
#12 0x00007ffff63e6318 in ?? () from /usr/lib/python2.7/dist-packages/gi/_gi.so
#13 0x00000000004c9fec in PyEval_EvalFrameEx ()
#14 0x00000000004ccee6 in PyEval_EvalCodeEx ()
#15 0x00000000004c5da8 in PyEval_EvalFrameEx ()
#16 0x00000000004ccee6 in PyEval_EvalCodeEx ()
#17 0x00000000005771c0 in ?? ()
#18 0x00000000004824c6 in PyObject_Call ()
#19 0x0000000000486086 in PyEval_CallObjectWithKeywords ()
#20 0x00007ffff63e4a46 in ?? () from /usr/lib/python2.7/dist-packages/gi/_gi.so
#21 0x00007ffff5f60804 in g_closure_invoke (closure=0xdde300,
    return_value=0x0, n_param_values=1, param_values=0xee2820,
    invocation_hint=<optimized out>)
    at /tmp/buildd/glib2.0-2.30.2/./gobject/gclosure.c:774
#22 0x00007ffff5f7278a in signal_emit_unlocked_R (node=<optimized out>,
    detail=0, instance=0xddc2e0, emission_return=0x0,
    instance_and_params=0xee2820)
    at /tmp/buildd/glib2.0-2.30.2/./gobject/gsignal.c:3272
#23 0x00007ffff5f7be11 in g_signal_emit_valist (instance=<optimized out>,
    signal_id=<optimized out>, detail=<optimized out>,
    var_args=<optimized out>)
    at /tmp/buildd/glib2.0-2.30.2/./gobject/gsignal.c:3003
#24 0x00007ffff5f7bfb2 in g_signal_emit (instance=<optimized out>,
    signal_id=<optimized out>, detail=<optimized out>)
    at /tmp/buildd/glib2.0-2.30.2/./gobject/gsignal.c:3060
#25 0x00007ffff37f66cd in gtk_real_button_released (button=0xddc2e0)
    at /tmp/buildd/gtk+3.0-3.2.3/./gtk/gtkbutton.c:1826
#26 0x00007ffff5f60804 in g_closure_invoke (closure=0xc5aab0,
    return_value=0x0, n_param_values=1, param_values=0xee2800,
    invocation_hint=<optimized out>)
    at /tmp/buildd/glib2.0-2.30.2/./gobject/gclosure.c:774
#27 0x00007ffff5f71f7a in signal_emit_unlocked_R (node=<optimized out>,
    detail=0, instance=0xddc2e0, emission_return=0x0,
    instance_and_params=0xee2800)
    at /tmp/buildd/glib2.0-2.30.2/./gobject/gsignal.c:3202
#28 0x00007ffff5f7be11 in g_signal_emit_valist (instance=<optimized out>,
    signal_id=<optimized out>, detail=<optimized out>,
    var_args=<optimized out>)
    at /tmp/buildd/glib2.0-2.30.2/./gobject/gsignal.c:3003
#29 0x00007ffff5f7bfb2 in g_signal_emit (instance=<optimized out>,
    signal_id=<optimized out>, detail=<optimized out>)
    at /tmp/buildd/glib2.0-2.30.2/./gobject/gsignal.c:3060
#30 0x00007ffff37f566d in gtk_button_button_release (widget=<optimized out>,
    event=<optimized out>) at /tmp/buildd/gtk+3.0-3.2.3/./gtk/gtkbutton.c:1718
#31 0x00007ffff38b3088 in _gtk_marshal_BOOLEAN__BOXED (closure=0xbd7780,
    return_value=0x7fffffffd3b0, n_param_values=<optimized out>,
    param_values=0xee34f0, invocation_hint=<optimized out>,
    marshal_data=<optimized out>)
    at /tmp/buildd/gtk+3.0-3.2.3/./gtk/gtkmarshalers.c:85
#32 0x00007ffff5f60804 in g_closure_invoke (closure=0xbd7780,
    return_value=0x7fffffffd3b0, n_param_values=2, param_values=0xee34f0,
    invocation_hint=<optimized out>)
    at /tmp/buildd/glib2.0-2.30.2/./gobject/gclosure.c:774
#33 0x00007ffff5f725bf in signal_emit_unlocked_R (node=<optimized out>,
    detail=0, instance=0xddc2e0, emission_return=0x7fffffffd510,
    instance_and_params=0xee34f0)
    at /tmp/buildd/glib2.0-2.30.2/./gobject/gsignal.c:3310
#34 0x00007ffff5f7bbe3 in g_signal_emit_valist (instance=<optimized out>,
    signal_id=<optimized out>, detail=<optimized out>,
    var_args=<optimized out>)
    at /tmp/buildd/glib2.0-2.30.2/./gobject/gsignal.c:3013
#35 0x00007ffff5f7bfb2 in g_signal_emit (instance=<optimized out>,
    signal_id=<optimized out>, detail=<optimized out>)
    at /tmp/buildd/glib2.0-2.30.2/./gobject/gsignal.c:3060
#36 0x00007ffff39dfaf9 in gtk_widget_event_internal (widget=0xddc2e0,
    event=0xdcf580) at /tmp/buildd/gtk+3.0-3.2.3/./gtk/gtkwidget.c:6132
#37 0x00007ffff38b27fa in gtk_propagate_event (widget=0xddc2e0, event=0xdcf580)
    at /tmp/buildd/gtk+3.0-3.2.3/./gtk/gtkmain.c:2624
#38 0x00007ffff38b2bfb in gtk_main_do_event (event=0xdcf580)
    at /tmp/buildd/gtk+3.0-3.2.3/./gtk/gtkmain.c:1889
#39 0x00007ffff3524702 in gdk_event_source_dispatch (source=<optimized out>,
    callback=<optimized out>, user_data=<optimized out>)
    at /tmp/buildd/gtk+3.0-3.2.3/./gdk/x11/gdkeventsource.c:360
#40 0x00007ffff54830cf in g_main_dispatch (context=0xc920f0)
    at /tmp/buildd/glib2.0-2.30.2/./glib/gmain.c:2442
#41 g_main_context_dispatch (context=0xc920f0)
    at /tmp/buildd/glib2.0-2.30.2/./glib/gmain.c:2998
#42 0x00007ffff54838c8 in g_main_context_iterate (context=0xc920f0,
    block=<optimized out>, dispatch=1, self=<optimized out>)
    at /tmp/buildd/glib2.0-2.30.2/./glib/gmain.c:3076
#43 0x00007ffff5483e02 in g_main_loop_run (loop=0xd471b0)
    at /tmp/buildd/glib2.0-2.30.2/./glib/gmain.c:3284
#44 0x00007ffff38b1fdd in gtk_main ()
    at /tmp/buildd/gtk+3.0-3.2.3/./gtk/gtkmain.c:1362
#45 0x00007ffff5b4a7bc in ffi_call_unix64 ()
   from /usr/lib/x86_64-linux-gnu/libffi.so.5
#46 0x00007ffff5b4a237 in ffi_call ()
   from /usr/lib/x86_64-linux-gnu/libffi.so.5
#47 0x00007ffff61abbc0 in ?? () from /usr/lib/libgirepository-1.0.so.1
#48 0x00007ffff61acf2e in g_function_info_invoke ()
   from /usr/lib/libgirepository-1.0.so.1
#49 0x00007ffff63e6318 in ?? () from /usr/lib/python2.7/dist-packages/gi/_gi.so
#50 0x00000000004c9fec in PyEval_EvalFrameEx ()
#51 0x00000000004ccee6 in PyEval_EvalCodeEx ()
#52 0x00000000004c5da8 in PyEval_EvalFrameEx ()
#53 0x00000000004ccee6 in PyEval_EvalCodeEx ()
#54 0x0000000000577901 in PyRun_FileExFlags ()
#55 0x0000000000577b37 in PyRun_SimpleFileExFlags ()
#56 0x0000000000550497 in Py_Main ()
#57 0x00007ffff69a1ead in __libc_start_main (main=<optimized out>,
    argc=<optimized out>, ubp_av=<optimized out>, init=<optimized out>,
    fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffffffe2f8)
    at libc-start.c:228
#58 0x000000000041dea1 in _start ()