(gdb) bt
#0  0x0014cb71 in bt_machine_get_voice_param_group (self=0x85211d8, voice=0) at src/lib/core/machine.c:2037
#1  0x00151436 in bt_pattern_resize_data_voices (voices=<optimized out>, self=0x84dc118) at src/lib/core/pattern.c:181
#2  bt_pattern_on_voices_changed (machine=0x85211d8, arg=0x0, user_data=0x84dc118) at src/lib/core/pattern.c:200
#3  0x0015161c in bt_pattern_constructed (object=0x84dc118) at src/lib/core/pattern.c:1196
#4  0x00a311ba in g_object_newv (object_type=137684248, n_parameters=5, parameters=0x879c0b8) at /build/buildd/glib2.0-2.32.3/./gobject/gobject.c:1741
#5  0x00a31543 in g_object_new_valist (object_type=137684248, first_property_name=0x184aa8 "song", var_args=0xbfffb2c0 "\220\304J\b\346 \025") at /build/buildd/glib2.0-2.32.3/./gobject/gobject.c:1830
#6  0x00a317a0 in g_object_new (object_type=137684248, first_property_name=0x184aa8 "song") at /build/buildd/glib2.0-2.32.3/./gobject/gobject.c:1545
#7  0x0015215e in bt_pattern_new (song=0x84ac490, id=0x879bfb8 "Jeskola-Bass-3 00", name=0x87095d8 "00", length=16, machine=0x85211d8) at src/lib/core/pattern.c:316
#8  0x08074b40 in add_new_pattern (self=<optimized out>, machine=0x85211d8) at src/ui/edit/main-page-patterns.c:1828
#9  0x08074ff9 in on_machine_added (setup=0x84a8968, machine=0x85211d8, user_data=0x84570c0) at src/ui/edit/main-page-patterns.c:2167
#10 0x00a2d603 in g_cclosure_marshal_VOID__OBJECT (closure=0x86cbef0, return_value=0x0, n_param_values=2, param_values=0xbfffb540, invocation_hint=0xbfffb4c0, marshal_data=0x0) at /build/buildd/glib2.0-2.32.3/./gobject/gmarshal.c:1272
#11 0x00a2a484 in g_closure_invoke (closure=0x86cbef0, return_value=0x0, n_param_values=2, param_values=0xbfffb540, invocation_hint=0xbfffb4c0) at /build/buildd/glib2.0-2.32.3/./gobject/gclosure.c:777
#12 0x00a3c0d9 in signal_emit_unlocked_R (node=0x851c338, detail=0, instance=0x84a8968, emission_return=0x0, instance_and_params=0xbfffb540) at /build/buildd/glib2.0-2.32.3/./gobject/gsignal.c:3547
#13 0x00a442dc in g_signal_emit_valist (instance=0x84a8968, signal_id=422, detail=0, var_args=0xbfffb750 "") at /build/buildd/glib2.0-2.32.3/./gobject/gsignal.c:3296
#14 0x00a44453 in g_signal_emit (instance=0x84a8968, signal_id=422, detail=0) at /build/buildd/glib2.0-2.32.3/./gobject/gsignal.c:3352
#15 0x0015ea09 in bt_setup_add_machine (self=0x84a8968, machine=0x85211d8) at src/lib/core/setup.c:1197
#16 0x0016ee66 in bt_source_machine_constructed (object=0x85211d8) at src/lib/core/source-machine.c:229
#17 bt_source_machine_constructed (object=0x85211d8) at src/lib/core/source-machine.c:191