Comment 2 for bug 1127251

StacktraceTop:
 emit_upstart_signal (signal=0xb3d1e0 "@\322\263") at seat.c:303
 va_to_ffi_type (storage=<optimized out>, va=0xffffffffffffff88, gtype=0) at /build/buildd/glib2.0-2.35.8/./gobject/gclosure.c:1311
 g_cclosure_marshal_generic_va (closure=<error reading variable: Cannot access memory at address 0xffffffffffffff20>, closure@entry=<error reading variable: Cannot access memory at address 0x8>, return_value=<error reading variable: Cannot access memory at address 0xffffffffffffff30>, instance=<error reading variable: Cannot access memory at address 0xffffffffffffff68>, args_list=<optimized out>, marshal_data=<error reading variable: Cannot access memory at address 0xffffffffffffff18>, n_params=<error reading variable: Cannot access memory at address 0xffffffffffffff4c>, param_types=<error reading variable: Cannot access memory at address 0x10>) at /build/buildd/glib2.0-2.35.8/./gobject/gclosure.c:1525