(C++) Nothing to be done for 'first'

 

make error.

 

 

 

 

 

Full error message

 

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Running build steps for project MyProject... Configuration unchanged, skipping QMake step. Starting: /usr/bin/make -w make: Entering directory '/MyProjectFolder' make: Nothing to be done for 'first'. make: Leaving directory '/MyProjectFolder' Exited with code 0.

 

 

 

 

 

 

Cause

 

IDE: Qt Creator 1.2.1

Compiler: G++ 4.4.1

Project type: Qt4 Console Application

 

MyProject.pro code:

 

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#------------------------------------------------- # # Project created by QtCreator 2010-04-24T14:22:38 # #------------------------------------------------- TARGET = MyProject CONFIG += console CONFIG -= app_bundle TEMPLATE = app SOURCES += main.cpp

 

main.cpp code:

 

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#include <QtCore/QCoreApplication> #include <QGraphicsScene> #include <QGraphicsView> int main() {   QGraphicsScene scene;   scene.addText("Hello, world!");   QGraphicsView view(&scene);   while (1)   {     view.show();   } }

 

Application output

 

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Starting /MyProject... The program has unexpectedly finished.

 

The project had already run once.

 

 

 

 

 

Solution

 

This make error might not be an error. Nothing to be done for 'first' denotes that the file main.cpp needs not to be recompiled to main.o, because the source code of main.cpp has not changed. This saves the programmer needless compiling time.

 

After removing the file main.o the following compile output (re)appears:

 

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Running build steps for project MyProject... Configuration unchanged, skipping QMake step. Starting: /usr/bin/make -w make: Entering directory '/MyProjectFolder' g++ -c -pipe -g -Wall -W -D_REENTRANT -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I. -o main.o main.cpp g++ -o MyProject main.o -L/usr/lib -lQtGui -lQtCore -lpthread make: Leaving directory '/MyProjectFolder' Exited with code 0.