valgrind back-trace including symbol names: ==1026== Invalid read of size 8 ==1026== at 0x8307EC2: ss_get_active_cb (gtkapplication-dbus.c:251) ==1026== by 0x6FA1DA3: g_task_return_now (gtask.c:1309) ==1026== by 0x6FA29F2: g_task_return (gtask.c:1378) ==1026== by 0x6FA29F2: g_task_return (gtask.c:1335) ==1026== by 0x7009C6B: reply_cb (gdbusproxy.c:2571) ==1026== by 0x6FA1DA3: g_task_return_now (gtask.c:1309) ==1026== by 0x6FA29F2: g_task_return (gtask.c:1378) ==1026== by 0x6FA29F2: g_task_return (gtask.c:1335) ==1026== by 0x6FFD8C1: g_dbus_connection_call_done (gdbusconnection.c:5885) ==1026== by 0x6FA1DA3: g_task_return_now (gtask.c:1309) ==1026== by 0x6FA1DD8: complete_in_idle_cb (gtask.c:1323) ==1026== by 0x5F70AAD: ??? (in /usr/lib64/libglib-2.0.so.0.7600.1) ==1026== by 0x5F74F95: g_main_context_dispatch (in /usr/lib64/libglib-2.0.so.0.7600.1) ==1026== by 0x5F75357: ??? (in /usr/lib64/libglib-2.0.so.0.7600.1) ==1026== Address 0xf9bda48 is 24 bytes inside a block of size 176 free'd ==1026== at 0x484617B: free (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so) ==1026== by 0x5F7BD58: g_free_sized (in /usr/lib64/libglib-2.0.so.0.7600.1) ==1026== by 0x71110C2: g_type_free_instance (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==1026== by 0x7FD5760: gtk_application_shutdown (gtkapplication.c:321) ==1026== by 0x70EE6E8: ??? (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==1026== by 0x7108725: g_signal_emit_valist (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==1026== by 0x7108A5E: g_signal_emit (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==1026== by 0x6FD09E9: g_application_run (gapplication.c:2579) ==1026== by 0x6568BAF: (below main) (in /usr/lib64/libc.so.6) ==1026== Block was alloc'd at ==1026== at 0x48485EF: calloc (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so) ==1026== by 0x5F7BCB0: g_malloc0 (in /usr/lib64/libglib-2.0.so.0.7600.1) ==1026== by 0x7110B33: g_type_create_instance (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==1026== by 0x70F453F: ??? (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==1026== by 0x70F5BAF: g_object_new_with_properties (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==1026== by 0x70F69A0: g_object_new (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==1026== by 0x7FD81F6: UnknownInlinedFun (gtkapplicationimpl.c:188) ==1026== by 0x7FD81F6: gtk_application_startup (gtkapplication.c:306) ==1026== by 0x70EE4EF: g_closure_invoke (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==1026== by 0x71015F4: ??? (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==1026== by 0x71088E5: g_signal_emit_valist (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==1026== by 0x7108A5E: g_signal_emit (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==1026== by 0x6FD0091: g_application_register (gapplication.c:2213) ==1026== ==1026== Invalid read of size 4 ==1026== at 0x8307ED4: UnknownInlinedFun (gtkapplication.c:1671) ==1026== by 0x8307ED4: ss_get_active_cb (gtkapplication-dbus.c:251) ==1026== by 0x6FA1DA3: g_task_return_now (gtask.c:1309) ==1026== by 0x6FA29F2: g_task_return (gtask.c:1378) ==1026== by 0x6FA29F2: g_task_return (gtask.c:1335) ==1026== by 0x7009C6B: reply_cb (gdbusproxy.c:2571) ==1026== by 0x6FA1DA3: g_task_return_now (gtask.c:1309) ==1026== by 0x6FA29F2: g_task_return (gtask.c:1378) ==1026== by 0x6FA29F2: g_task_return (gtask.c:1335) ==1026== by 0x6FFD8C1: g_dbus_connection_call_done (gdbusconnection.c:5885) ==1026== by 0x6FA1DA3: g_task_return_now (gtask.c:1309) ==1026== by 0x6FA1DD8: complete_in_idle_cb (gtask.c:1323) ==1026== by 0x5F70AAD: ??? (in /usr/lib64/libglib-2.0.so.0.7600.1) ==1026== by 0x5F74F95: g_main_context_dispatch (in /usr/lib64/libglib-2.0.so.0.7600.1) ==1026== by 0x5F75357: ??? (in /usr/lib64/libglib-2.0.so.0.7600.1) ==1026== Address 0xaaaaaaaaaaaaa9ea is not stack'd, malloc'd or (recently) free'd