(gdb) bt
#0  0x00007fffeedbef79 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
#1  0x00007fffeedc2388 in __GI_abort () at abort.c:89
#2  0x00007fffeedb7e36 in __assert_fail_base (fmt=0x7fffeef09718 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=assertion@entry=0x12ccb00 "!this->is_null( n )", file=file@entry=0x12cc98c "/usr/include/boost/ptr_container/ptr_sequence_adapter.hpp", line=line@entry=326, function=function@entry=0x12cc9c6 "reference boost::ptr_sequence_adapter<Inkscape::UI::Dialogs::ColorItem, std::vector<void *, std::allocator<void *> >, boost::heap_clone_allocator>::operator[](size_type) [T = Inkscape::UI::Dialogs::Co"...) at assert.c:92
#3  0x00007fffeedb7ee2 in __GI___assert_fail (assertion=0x12ccb00 "!this->is_null( n )", file=0x12cc98c "/usr/include/boost/ptr_container/ptr_sequence_adapter.hpp", line=326, function=0x12cc9c6 "reference boost::ptr_sequence_adapter<Inkscape::UI::Dialogs::ColorItem, std::vector<void *, std::allocator<void *> >, boost::heap_clone_allocator>::operator[](size_type) [T = Inkscape::UI::Dialogs::Co"...) at assert.c:101
#4  0x0000000000ba6c0b in boost::ptr_sequence_adapter<Inkscape::UI::Dialogs::ColorItem, std::vector<void*, std::allocator<void*> >, boost::heap_clone_allocator>::operator[] (this=0x9266600, n=367) at /usr/include/boost/ptr_container/ptr_sequence_adapter.hpp:326
#5  0x0000000000d85783 in Inkscape::UI::Dialogs::SwatchesPanel::handleDefsModified (document=0x27129c0) at ../../src/ui/dialog/swatches.cpp:1057
#6  0x0000000000d8ed60 in sigc::pointer_functor1<SPDocument*, void>::operator() (this=0x3cbf4c0, _A_a1=@0x3cbf4c8: 0x27129c0) at /usr/include/sigc++-2.0/sigc++/functors/ptr_fun.h:111
#7  0x0000000000d8ed1f in sigc::adaptor_functor<sigc::pointer_functor1<SPDocument*, void> >::operator()<SPDocument*&> (this=0x3cbf4b8, _A_arg1=@0x3cbf4c8: 0x27129c0) at /usr/include/sigc++-2.0/sigc++/adaptors/adaptor_trait.h:84
#8  0x0000000000d8ece5 in sigc::bind_functor<-1, sigc::pointer_functor1<SPDocument*, void>, SPDocument*, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil>::operator() (this=0x3cbf4b0) at /usr/include/sigc++-2.0/sigc++/adaptors/bind.h:1110
#9  0x0000000000d8eca3 in sigc::hide_functor<-1, sigc::bind_functor<-1, sigc::pointer_functor1<SPDocument*, void>, SPDocument*, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil> >::operator()<SPObject* const&> (this=0x3cbf4a8) at /usr/include/sigc++-2.0/sigc++/adaptors/hide.h:96
#10 0x0000000000d8ec6b in sigc::hide_functor<-1, sigc::hide_functor<-1, sigc::bind_functor<-1, sigc::pointer_functor1<SPDocument*, void>, SPDocument*, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil> > >::operator()<SPObject* const&, unsigned int const&> (this=0x3cbf4a0, _A_a1=@0x7fffffffbe48: 0x8b1e040) at /usr/include/sigc++-2.0/sigc++/adaptors/hide.h:113
#11 0x0000000000d8ec2f in sigc::internal::slot_call2<sigc::hide_functor<-1, sigc::hide_functor<-1, sigc::bind_functor<-1, sigc::pointer_functor1<SPDocument*, void>, SPDocument*, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil> > >, void, SPObject*, unsigned int>::call_it (rep=0x3cbf470, a_1=@0x7fffffffbe48: 0x8b1e040, a_2=@0x7fffffffbe54: 2) at /usr/include/sigc++-2.0/sigc++/functors/slot.h:172
#12 0x00000000006fceea in sigc::internal::signal_emit2<void, SPObject*, unsigned int, sigc::nil>::emit (impl=0x3cbfea0, _A_a1=@0x7fffffffbe48: 0x8b1e040, _A_a2=@0x7fffffffbe54: 2) at /usr/include/sigc++-2.0/sigc++/signal.h:1252
#13 0x00000000006fcc09 in sigc::signal2<void, SPObject*, unsigned int, sigc::nil>::emit (this=0x8b1e0d0, _A_a1=@0x7fffffffbe48: 0x8b1e040, _A_a2=@0x7fffffffbe54: 2) at /usr/include/sigc++-2.0/sigc++/signal.h:2891
#14 0x00000000006fb377 in SPObject::emitModified (this=0x8b1e040, flags=2) at ../../src/sp-object.cpp:1217
#15 0x00000000006b42fa in SPGroup::modified (this=0x88f10b0, flags=0) at ../../src/sp-item-group.cpp:227
#16 0x0000000000711b05 in SPRoot::modified (this=0x88f10b0, flags=2) at ../../src/sp-root.cpp:315
#17 0x00000000006fb355 in SPObject::emitModified (this=0x88f10b0, flags=2) at ../../src/sp-object.cpp:1215
#18 0x00000000004fbaf5 in SPDocument::_emitModified (this=0x27129c0) at ../../src/document.cpp:905
#19 0x00000000004fc6f0 in SPDocument::_updateDocument (this=0x27129c0) at ../../src/document.cpp:1072
#20 0x00000000004fc79d in SPDocument::ensureUpToDate (this=0x27129c0) at ../../src/document.cpp:1095
#21 0x000000000050eda1 in Inkscape::DocumentUndo::maybeDone (doc=0x27129c0, key=0x0, event_type=1, event_description=...) at ../../src/document-undo.cpp:167
#22 0x000000000050ec40 in Inkscape::DocumentUndo::done (doc=0x27129c0, event_type=1, event_description=...) at ../../src/document-undo.cpp:112
#23 0x0000000000f0a6a1 in Inkscape::UI::Widget::PageSizer::setDim (this=0x940a770, w=..., h=..., changeList=true) at ../../src/ui/widget/page-sizer.cpp:488
#24 0x0000000000f09ff3 in Inkscape::UI::Widget::PageSizer::on_value_changed (this=0x940a770) at ../../src/ui/widget/page-sizer.cpp:711
#25 0x0000000000f0d300 in sigc::bound_mem_functor0<void, Inkscape::UI::Widget::PageSizer>::operator() (this=0x95f6eb8) at /usr/include/sigc++-2.0/sigc++/functors/mem_fun.h:1787
#26 0x0000000000f0d26c in sigc::adaptor_functor<sigc::bound_mem_functor0<void, Inkscape::UI::Widget::PageSizer> >::operator() (this=0x95f6eb0) at /usr/include/sigc++-2.0/sigc++/adaptors/adaptor_trait.h:251
#27 0x0000000000f0d244 in sigc::internal::slot_call0<sigc::bound_mem_functor0<void, Inkscape::UI::Widget::PageSizer>, void>::call_it (rep=0x95f6e80) at /usr/include/sigc++-2.0/sigc++/functors/slot.h:103
#28 0x00007ffff5777038 in Glib::SignalProxyNormal::slot0_void_callback(_GObject*, void*) () from /usr/lib/x86_64-linux-gnu/libglibmm-2.4.so.1
#29 0x00007fffefb9e3b8 in g_closure_invoke (closure=0x95f6f30, return_value=0x0, n_param_values=1, param_values=0x7fffffffc5c0, invocation_hint=0x7fffffffc560) at /build/buildd/glib2.0-2.40.0/./gobject/gclosure.c:768
#30 0x00007fffefbaffd1 in signal_emit_unlocked_R (node=node@entry=0x38b8230, detail=detail@entry=0, instance=instance@entry=0x9658620, emission_return=emission_return@entry=0x0, instance_and_params=instance_and_params@entry=0x7fffffffc5c0) at /build/buildd/glib2.0-2.40.0/./gobject/gsignal.c:3621
#31 0x00007fffefbb7a29 in g_signal_emit_valist (instance=<optimized out>, signal_id=<optimized out>, detail=<optimized out>, var_args=var_args@entry=0x7fffffffc748) at /build/buildd/glib2.0-2.40.0/./gobject/gsignal.c:3307
#32 0x00007fffefbb7ce2 in g_signal_emit (instance=instance@entry=0x9658620, signal_id=<optimized out>, detail=detail@entry=0) at /build/buildd/glib2.0-2.40.0/./gobject/gsignal.c:3363
#33 0x00007ffff6c40e41 in gtk_spin_button_value_changed (adjustment=0x3ac7770, spin_button=0x9658620) at /build/buildd/gtk+2.0-2.24.23/gtk/gtkspinbutton.c:1288
#34 0x00007fffefb9e3b8 in g_closure_invoke (closure=0x3a9b690, return_value=0x0, n_param_values=1, param_values=0x7fffffffc9e0, invocation_hint=0x7fffffffc980) at /build/buildd/glib2.0-2.40.0/./gobject/gclosure.c:768
#35 0x00007fffefbafd3d in signal_emit_unlocked_R (node=node@entry=0x32be600, detail=detail@entry=0, instance=instance@entry=0x3ac7770, emission_return=emission_return@entry=0x0, instance_and_params=instance_and_params@entry=0x7fffffffc9e0) at /build/buildd/glib2.0-2.40.0/./gobject/gsignal.c:3551
#36 0x00007fffefbb7a29 in g_signal_emit_valist (instance=<optimized out>, signal_id=<optimized out>, detail=<optimized out>, var_args=var_args@entry=0x7fffffffcb68) at /build/buildd/glib2.0-2.40.0/./gobject/gsignal.c:3307
#37 0x00007fffefbb7ce2 in g_signal_emit (instance=instance@entry=0x3ac7770, signal_id=<optimized out>, detail=detail@entry=0) at /build/buildd/glib2.0-2.40.0/./gobject/gsignal.c:3363
#38 0x00007ffff6b1fdfa in IA__gtk_adjustment_value_changed (adjustment=0x3ac7770) at /build/buildd/gtk+2.0-2.24.23/gtk/gtkadjustment.c:668
#39 0x00007ffff6c42223 in IA__gtk_spin_button_set_value (spin_button=0x9658620, value=1000) at /build/buildd/gtk+2.0-2.24.23/gtk/gtkspinbutton.c:2020
#40 0x00007ffff6c42ab9 in IA__gtk_spin_button_update (spin_button=spin_button@entry=0x9658620) at /build/buildd/gtk+2.0-2.24.23/gtk/gtkspinbutton.c:2349
#41 0x00007ffff6c42dbf in gtk_spin_button_activate (entry=0x9658620) at /build/buildd/gtk+2.0-2.24.23/gtk/gtkspinbutton.c:1428
#42 0x00007ffff7a204d0 in Gtk::Entry_Class::activate_callback(_GtkEntry*) () from /usr/lib/x86_64-linux-gnu/libgtkmm-2.4.so.1
#43 0x00007fffefb9e3b8 in g_closure_invoke (closure=0x38b5650, return_value=0x7fffffffcf80, n_param_values=1, param_values=0x9574a00, invocation_hint=0x7fffffffce40) at /build/buildd/glib2.0-2.40.0/./gobject/gclosure.c:768
#44 0x00007fffefbafafb in signal_emit_unlocked_R (node=node@entry=0x38b5680, detail=detail@entry=0, instance=instance@entry=0x9658620, emission_return=emission_return@entry=0x7fffffffcf80, instance_and_params=instance_and_params@entry=0x9574a00) at /build/buildd/glib2.0-2.40.0/./gobject/gsignal.c:3589
#45 0x00007fffefbb6bf1 in g_signal_emitv (instance_and_params=instance_and_params@entry=0x9574a00, signal_id=signal_id@entry=228, detail=detail@entry=0, return_value=return_value@entry=0x7fffffffcf80) at /build/buildd/glib2.0-2.40.0/./gobject/gsignal.c:3045
#46 0x00007ffff6b27bed in gtk_binding_entry_activate (entry=<optimized out>, object=object@entry=0x9658620) at /build/buildd/gtk+2.0-2.24.23/gtk/gtkbindings.c:537
#47 0x00007ffff6b28101 in binding_match_activate (pspec_list=pspec_list@entry=0x9633d10, object=object@entry=0x9658620, path_length=8, path=path@entry=0x96338f0 "GtkEntry", path_reversed=path_reversed@entry=0x9505300 "yrtnEktG", unbound=unbound@entry=0x7fffffffd0c8) at /build/buildd/gtk+2.0-2.24.23/gtk/gtkbindings.c:1124
#48 0x00007ffff6b2834a in gtk_bindings_activate_list (object=object@entry=0x9658620, entries=entries@entry=0x9633d00, is_release=<optimized out>) at /build/buildd/gtk+2.0-2.24.23/gtk/gtkbindings.c:1269
#49 0x00007ffff6b293b7 in IA__gtk_bindings_activate_event (object=0x9658620, event=0x4ee7dd0) at /build/buildd/gtk+2.0-2.24.23/gtk/gtkbindings.c:1364
#50 0x00007ffff6b6c644 in gtk_entry_key_press (widget=0x9658620, event=0x4ee7dd0) at /build/buildd/gtk+2.0-2.24.23/gtk/gtkentry.c:4091
#51 0x00007ffff7a9bd04 in Gtk::Widget::on_key_press_event(_GdkEventKey*) () from /usr/lib/x86_64-linux-gnu/libgtkmm-2.4.so.1
#52 0x00007ffff7a9dd04 in Gtk::Widget_Class::key_press_event_callback(_GtkWidget*, _GdkEventKey*) () from /usr/lib/x86_64-linux-gnu/libgtkmm-2.4.so.1
#53 0x00007ffff6bd4815 in _gtk_marshal_BOOLEAN__BOXED (closure=0x1bd1310, return_value=0x7fffffffd2b0, n_param_values=<optimized out>, param_values=0x7fffffffd360, invocation_hint=<optimized out>, marshal_data=0x7ffff7a9dcb0 <Gtk::Widget_Class::key_press_event_callback(_GtkWidget*, _GdkEventKey*)>) at /build/buildd/gtk+2.0-2.24.23/gtk/gtkmarshalers.c:86
#54 0x00007fffefb9e332 in g_closure_invoke (closure=0x1bd1310, return_value=0x7fffffffd2b0, n_param_values=2, param_values=0x7fffffffd360, invocation_hint=0x7fffffffd300) at /build/buildd/glib2.0-2.40.0/./gobject/gclosure.c:768
#55 0x00007fffefbafafb in signal_emit_unlocked_R (node=node@entry=0x1bd1360, detail=detail@entry=0, instance=instance@entry=0x9658620, emission_return=emission_return@entry=0x7fffffffd430, instance_and_params=instance_and_params@entry=0x7fffffffd360) at /build/buildd/glib2.0-2.40.0/./gobject/gsignal.c:3589
#56 0x00007fffefbb76f9 in g_signal_emit_valist (instance=<optimized out>, signal_id=<optimized out>, detail=<optimized out>, var_args=var_args@entry=0x7fffffffd4f8) at /build/buildd/glib2.0-2.40.0/./gobject/gsignal.c:3317
#57 0x00007fffefbb7ce2 in g_signal_emit (instance=instance@entry=0x9658620, signal_id=<optimized out>, detail=detail@entry=0) at /build/buildd/glib2.0-2.40.0/./gobject/gsignal.c:3363
#58 0x00007ffff6ce4724 in gtk_widget_event_internal (widget=widget@entry=0x9658620, event=event@entry=0x4ee7dd0) at /build/buildd/gtk+2.0-2.24.23/gtk/gtkwidget.c:5010
#59 0x00007ffff6ce49f9 in IA__gtk_widget_event (widget=widget@entry=0x9658620, event=event@entry=0x4ee7dd0) at /build/buildd/gtk+2.0-2.24.23/gtk/gtkwidget.c:4807
#60 0x00007ffff6cf7f9b in IA__gtk_window_propagate_key_event (window=window@entry=0x95459b0, event=event@entry=0x4ee7dd0) at /build/buildd/gtk+2.0-2.24.23/gtk/gtkwindow.c:5199
#61 0x00007ffff6cfa69b in gtk_window_key_press_event (widget=0x95459b0, event=0x4ee7dd0) at /build/buildd/gtk+2.0-2.24.23/gtk/gtkwindow.c:5229
#62 0x00007ffff6bd4815 in _gtk_marshal_BOOLEAN__BOXED (closure=0x1bd1310, return_value=0x7fffffffd770, n_param_values=<optimized out>, param_values=0x7fffffffd820, invocation_hint=<optimized out>, marshal_data=0x7ffff6cfa670 <gtk_window_key_press_event>) at /build/buildd/gtk+2.0-2.24.23/gtk/gtkmarshalers.c:86
#63 0x00007fffefb9e3b8 in g_closure_invoke (closure=0x1bd1310, return_value=0x7fffffffd770, n_param_values=2, param_values=0x7fffffffd820, invocation_hint=0x7fffffffd7c0) at /build/buildd/glib2.0-2.40.0/./gobject/gclosure.c:768
#64 0x00007fffefbafafb in signal_emit_unlocked_R (node=node@entry=0x1bd1360, detail=detail@entry=0, instance=instance@entry=0x95459b0, emission_return=emission_return@entry=0x7fffffffd8f0, instance_and_params=instance_and_params@entry=0x7fffffffd820) at /build/buildd/glib2.0-2.40.0/./gobject/gsignal.c:3589
#65 0x00007fffefbb76f9 in g_signal_emit_valist (instance=<optimized out>, signal_id=<optimized out>, detail=<optimized out>, var_args=var_args@entry=0x7fffffffd9b8) at /build/buildd/glib2.0-2.40.0/./gobject/gsignal.c:3317
#66 0x00007fffefbb7ce2 in g_signal_emit (instance=instance@entry=0x95459b0, signal_id=<optimized out>, detail=detail@entry=0) at /build/buildd/glib2.0-2.40.0/./gobject/gsignal.c:3363
#67 0x00007ffff6ce4724 in gtk_widget_event_internal (widget=widget@entry=0x95459b0, event=event@entry=0x4ee7dd0) at /build/buildd/gtk+2.0-2.24.23/gtk/gtkwidget.c:5010
#68 0x00007ffff6ce49f9 in IA__gtk_widget_event (widget=widget@entry=0x95459b0, event=event@entry=0x4ee7dd0) at /build/buildd/gtk+2.0-2.24.23/gtk/gtkwidget.c:4807
#69 0x00007ffff6bd3097 in IA__gtk_propagate_event (widget=0x95459b0, event=0x4ee7dd0) at /build/buildd/gtk+2.0-2.24.23/gtk/gtkmain.c:2483
#70 0x00007ffff6bd337b in IA__gtk_main_do_event (event=0x4ee7dd0) at /build/buildd/gtk+2.0-2.24.23/gtk/gtkmain.c:1699
#71 0x0000000000483e0f in snooper (event=0x4ee7dd0) at ../../src/main.cpp:1009
#72 0x00007ffff684e1ec in gdk_event_dispatch (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at /build/buildd/gtk+2.0-2.24.23/gdk/x11/gdkevents-x11.c:2403
#73 0x00007fffef8cee04 in g_main_dispatch (context=0x1ba9390) at /build/buildd/glib2.0-2.40.0/./glib/gmain.c:3064
#74 g_main_context_dispatch (context=context@entry=0x1ba9390) at /build/buildd/glib2.0-2.40.0/./glib/gmain.c:3663
#75 0x00007fffef8cf048 in g_main_context_iterate (context=0x1ba9390, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at /build/buildd/glib2.0-2.40.0/./glib/gmain.c:3734
#76 0x00007fffef8cf30a in g_main_loop_run (loop=0x4e74070) at /build/buildd/glib2.0-2.40.0/./glib/gmain.c:3928
#77 0x00007ffff6bd2447 in IA__gtk_main () at /build/buildd/gtk+2.0-2.24.23/gtk/gtkmain.c:1271
#78 0x0000000000483537 in sp_main_gui (argc=1, argv=0x7fffffffdff8) at ../../src/main.cpp:1075
#79 0x0000000000482dce in main (argc=1, argv=0x7fffffffdff8) at ../../src/main.cpp:789