Valgrind tells the following: ==450== Invalid read of size 8 ==450== at 0x8307EC2: ??? (in /usr/lib64/libgtk-3.so.0.2405.32) ==450== by 0x6FA1DA3: ??? (in /usr/lib64/libgio-2.0.so.0.7600.1) ==450== by 0x6FA29F2: ??? (in /usr/lib64/libgio-2.0.so.0.7600.1) ==450== by 0x7009C6B: ??? (in /usr/lib64/libgio-2.0.so.0.7600.1) ==450== by 0x6FA1DA3: ??? (in /usr/lib64/libgio-2.0.so.0.7600.1) ==450== by 0x6FA29F2: ??? (in /usr/lib64/libgio-2.0.so.0.7600.1) ==450== by 0x6FFD8C1: ??? (in /usr/lib64/libgio-2.0.so.0.7600.1) ==450== by 0x6FA1DA3: ??? (in /usr/lib64/libgio-2.0.so.0.7600.1) ==450== by 0x6FA1DD8: ??? (in /usr/lib64/libgio-2.0.so.0.7600.1) ==450== by 0x5F70AAD: ??? (in /usr/lib64/libglib-2.0.so.0.7600.1) ==450== by 0x5F74F95: g_main_context_dispatch (in /usr/lib64/libglib-2.0.so.0.7600.1) ==450== by 0x5F75357: ??? (in /usr/lib64/libglib-2.0.so.0.7600.1) ==450== Address 0xf9bcff8 is 24 bytes inside a block of size 176 free'd ==450== at 0x484617B: free (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so) ==450== by 0x5F7BD58: g_free_sized (in /usr/lib64/libglib-2.0.so.0.7600.1) ==450== by 0x71110C2: g_type_free_instance (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==450== by 0x7FD5760: ??? (in /usr/lib64/libgtk-3.so.0.2405.32) ==450== by 0x70EE6E8: ??? (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==450== by 0x7108725: g_signal_emit_valist (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==450== by 0x7108A5E: g_signal_emit (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==450== by 0x6FD09E9: g_application_run (in /usr/lib64/libgio-2.0.so.0.7600.1) ==450== by 0x6568BAF: (below main) (in /usr/lib64/libc.so.6) ==450== Block was alloc'd at ==450== at 0x48485EF: calloc (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so) ==450== by 0x5F7BCB0: g_malloc0 (in /usr/lib64/libglib-2.0.so.0.7600.1) ==450== by 0x7110B33: g_type_create_instance (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==450== by 0x70F453F: ??? (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==450== by 0x70F5BAF: g_object_new_with_properties (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==450== by 0x70F69A0: g_object_new (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==450== by 0x7FD81F6: ??? (in /usr/lib64/libgtk-3.so.0.2405.32) ==450== by 0x70EE4EF: g_closure_invoke (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==450== by 0x71015F4: ??? (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==450== by 0x71088E5: g_signal_emit_valist (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==450== by 0x7108A5E: g_signal_emit (in /usr/lib64/libgobject-2.0.so.0.7600.1) ==450== by 0x6FD0091: g_application_register (in /usr/lib64/libgio-2.0.so.0.7600.1) ==450== ==450== Invalid read of size 4 ==450== at 0x8307ED4: ??? (in /usr/lib64/libgtk-3.so.0.2405.32) ==450== by 0x6FA1DA3: ??? (in /usr/lib64/libgio-2.0.so.0.7600.1) ==450== by 0x6FA29F2: ??? (in /usr/lib64/libgio-2.0.so.0.7600.1) ==450== by 0x7009C6B: ??? (in /usr/lib64/libgio-2.0.so.0.7600.1) ==450== by 0x6FA1DA3: ??? (in /usr/lib64/libgio-2.0.so.0.7600.1) ==450== by 0x6FA29F2: ??? (in /usr/lib64/libgio-2.0.so.0.7600.1) ==450== by 0x6FFD8C1: ??? (in /usr/lib64/libgio-2.0.so.0.7600.1) ==450== by 0x6FA1DA3: ??? (in /usr/lib64/libgio-2.0.so.0.7600.1) ==450== by 0x6FA1DD8: ??? (in /usr/lib64/libgio-2.0.so.0.7600.1) ==450== by 0x5F70AAD: ??? (in /usr/lib64/libglib-2.0.so.0.7600.1) ==450== by 0x5F74F95: g_main_context_dispatch (in /usr/lib64/libglib-2.0.so.0.7600.1) ==450== by 0x5F75357: ??? (in /usr/lib64/libglib-2.0.so.0.7600.1) ==450== Address 0xaaaaaaaaaaaaa9ea is not stack'd, malloc'd or (recently) free'd