Cannot debug GUI App

[rsjethani]

Hi,
I am running Qt 5.2(downloaded binary) on Linux Mint 16 Cinnamon x86.
Created a simple GUI app.When I put a break point on a line or simply press F5 in debug mode ofcourse I get the following application output:
@Debugging starts
&"warning: GDB: Failed to set controlling terminal: Inappropriate ioctl for device\n"
Debugging has finished@

But the app runs as if ran it without debugging.Debugging is working with console app. Terminal setting "/usr/bin/gnome-terminal -x"

.pro file for the project:
@#-------------------------------------------------

Project created by QtCreator 2014-02-26T12:16:22

#-------------------------------------------------

QT += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = guitest
TEMPLATE = app

SOURCES += main.cpp
MainWindow.cpp

HEADERS += MainWindow.h

FORMS += MainWindow.ui@

The following questions are similar but not the same:

"1":http://qt-project.org/forums/viewthread/7036
"2":https://qt-project.org/forums/viewthread/32238
I am not able to understand the problem.
thanks.