Compiling a Qt Creator project programmatically

[Donald Duck]

I'm trying to compile a Qt Creator project programmatically. For this I'm using the following code:

QTemporaryFile temp;
ofstream pro(QString(temp.path() + "/project.pro").toLatin1().data());
pro << "(some stuff)";
pro.close();
ofstream cpp(QString(temp.path() + "/main.cpp").toLatin1().data());
cpp << "(some stuff)"
cpp.close();
ofstream user(QString(temp.path() + "/project.pro.user").toLatin1().data());
user << "(some stuff)";
user.close();
QProcess *qmake = new QProcess;
qmake->start("\"C:\\Qt\\Qt5.7.0_x86\\5.7\\msvc2015\\bin\\qmake.exe\" \"" + temp.path() + "/project.pro\" -r -spec win32-msvc2015");
QObject::connect(qmake, static_cast<void (QProcess::*)(int)>(&QProcess::finished), [=](int exitCode){
    if(exitCode != 0){
        QMessageBox::critical(window, "Error", "Could not compile. The process qmake.exe exited with code " + QString::number(exitCode));
    }
    else{
        QProcess *jom = new QProcess;
        jom->start("\"C:\\Qt\\Qt5.7.0_x86\\Tools\\QtCreator\\bin\\jom.exe\" \"" + temp.path() + "/build-project-Desktop_Qt_5_7_0_MSVC2015_32bit-Release\"");
        QObject::connect(jom, static_cast<void (QProcess::*)(int)>(&QProcess::finished), [=](int exitCode){
            if(exitCode == 0){
                QMessageBox::information(window, "Success", "The program was compiled successfully.");
            }
            else{
                QMessageBox::critical(window, "Error", "Could not compile. The process jom.exe exited with code " + QString::number(exitCode));
            }
        });
    }
});

The problem is that the program doesn't compile because jom.exe exits with code 2. But when I open the project in Qt Creator and compile it manually, it works just fine. What am I doing wrong?

[A Former User]

Hi! Two guesses: Wrong working directory, missing environment variables.