How to set .pro file about debug and release

[ktk]

The condition to check whether something is a "Debug" build is CONFIG(debug, debug|release)

[rajji_saini]

You can do something like:

CONFIG(debug, debug|release) {
CONFIG -= debug release
CONFIG += debug
QMAKE_POST_LINK = " "
}
CONFIG(release, debug|release) {
CONFIG -= debug release
CONFIG += release
QMAKE_POST_LINK = " "
}