Gdb/Mac: Tooltips in Watch window cannot show the value of arguments.

Steps:
1. Go-> preference->Debugger->General, check "use tooltips in main editor when debugging".
2. Start Debug a Qt Gui application or use the attachments.
3. Cursor Stay at on arguments "*argv[ ] ".
4 .Change Cursor stay on another different arguments, then Repeat step 3 .

Expected result:
Tooltips should be always show the right value of "argv" ,every time cursor stay on this arguments.

Actually result:.
According to the snapshot u can see ,sometimes tooltips cannot show the right value of the same arguments